Vulnerability-Lookup

GHSA-JJV6-8J6V-6J52

Vulnerability from github – Published: 2026-09-01 20:21 – Updated: 2026-09-01 20:21

Summary

league/commonmark: Denial of service in the SmartPunct and Attributes extensions

Details

Impact

Two first-party extensions contain quadratic parsing paths. Both ship with the library but must be explicitly registered on the Environment; neither is included in CommonMarkConverter, GithubFlavoredMarkdownConverter, or GithubFlavoredMarkdownExtension. Applications that do not register SmartPunctExtension or AttributesExtension are not affected by this advisory.

1. SmartPunctExtension — quote replacement recopies the whole text node (affected from 2.0.0).

ReplaceUnpairedQuotesListener converts each unpaired Quote node back to a Text node and merges it into its neighbours via AdjacentTextMerger. The merge reads the left node's literal into a local variable, appends to that variable, and writes it back — and because the read aliases the node's string, every append copies the entire accumulated literal rather than only the bytes added. The listener runs this once per surviving unpaired quote against the same continuously growing text node, so the same buffer is fully re-copied a linear number of times.

A 1.2 MB document of alternating text segments and apostrophes takes 34.9 seconds to convert, against 0.069 seconds for the same input with the extension not registered.

Hardened configuration makes this worse rather than better: QuoteParser appends the Quote node to the AST before pushing it onto the delimiter stack, so max_delimiters_per_line removes the quote-pairing work while leaving every node the listener must process.

2. AttributesExtension — block-level attribute runs re-scan their siblings (affected from 1.5.0).

AttributesListener::findTargetAndDirection() walks the entire remaining sibling chain for every block-level Attributes node whose target is the following node. The backward half of that walk returns immediately for such nodes, and the forward half stops only at a sibling that is not itself an attributes node — which a contiguous run never provides — so a run of k nodes costs k(k-1)/2 steps.

An input placing each {#a} on its own line, with a single reference definition to keep the run contiguous, takes 28.4 seconds at 16,000 attribute blocks while producing zero bytes of output.

This is the block-level counterpart of GHSA-g2gp-3wwq-f4ph, patched in 2.9.0. That fix is incomplete: the early break it introduced is guarded on the node being an AttributesInline, so block-level Attributes nodes still re-scan. Applications that upgraded to 2.9.0 specifically to address GHSA-g2gp-3wwq-f4ph remain exposed to this variant.

3. AttributesExtension — class lists are rebuilt on every merge (affected from 1.5.0).

AttributesHelper::mergeAttributes() round-trips the accumulated class list through explode and implode on each merge. An #id attribute assigns a scalar and skips the branch entirely, but a .class attribute appends to an array which is then imploded to a string, written to the target node, and read back on the next iteration — so the ith merge pays a cost proportional to i three separate times.

{.c} repeated 32,000 times takes 33.5 seconds, against 0.26 seconds for byte-identical input using {#a} — a 130x gap that widens with input size. Both the inline and the block-level attribute paths are affected.

Overall impact. An unauthenticated attacker who can submit Markdown to an affected application can consume disproportionate CPU time with a comparatively small request, occupying PHP workers and preventing legitimate requests from completing. The impact is limited to availability: no data is disclosed, rendered output is unchanged, and no rendering restriction is bypassed.

No library-level configuration gates any of these paths. For the Attributes extension in particular, neither the attributes/allow allow-list nor the on* event-handler hardening added in 2.7.0 has any effect, because the expensive work happens while parsing and resolving the AST, before any attribute filtering or rendering takes place.

Patches

The issues are patched in 2.9.1 and later:

Adjacent text merging now appends in place instead of reading, modifying, and writing back the whole literal, so a merge costs only the bytes added. This fixes the defect for every caller, not only the SmartPunct listener.
AttributesListener now records the runs it has already walked, so each contiguous run of block-level attribute nodes is scanned once rather than once per node.
Accumulated class lists no longer pass through mergeAttributes() repeatedly; the listener holds pending attributes and joins them in a single pass.

The SmartPunct path affects 2.0.0 through 2.9.0. The Attributes paths affect 1.5.0 through 2.9.0, including releases that already contain the 2.9.0 fix for GHSA-g2gp-3wwq-f4ph. The 1.x release line is no longer supported, so its users must upgrade to 2.9.1 or later.

Workarounds

If you cannot upgrade immediately:

Do not register SmartPunctExtension or AttributesExtension when converting untrusted Markdown. This fully removes the affected paths.
If either extension is required, impose a strict maximum input length before conversion. Because the cost is quadratic, even a modest cap must be small to meaningfully bound worst-case CPU time.

Restricting conversion to trusted users, applying strict execution-time limits, and rate-limiting requests reduce exposure but are not substitutes for upgrading. Configuration options including attributes/allow, max_delimiters_per_line, max_nesting_level, html_input, and allow_unsafe_links do not mitigate these issues.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "league/commonmark"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.5.0"
            },
            {
              "fixed": "2.9.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-1050",
      "CWE-407"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-01T20:21:45Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Impact\n\nTwo first-party extensions contain quadratic parsing paths. Both ship with the library but must be explicitly registered on the `Environment`; neither is included in `CommonMarkConverter`, `GithubFlavoredMarkdownConverter`, or `GithubFlavoredMarkdownExtension`. **Applications that do not register `SmartPunctExtension` or `AttributesExtension` are not affected by this advisory.**\n\n**1. `SmartPunctExtension` \u2014 quote replacement recopies the whole text node (affected from 2.0.0).**\n\n`ReplaceUnpairedQuotesListener` converts each unpaired `Quote` node back to a `Text` node and merges it into its neighbours via `AdjacentTextMerger`. The merge reads the left node\u0027s literal into a local variable, appends to that variable, and writes it back \u2014 and because the read aliases the node\u0027s string, every append copies the entire accumulated literal rather than only the bytes added. The listener runs this once per surviving unpaired quote against the same continuously growing text node, so the same buffer is fully re-copied a linear number of times.\n\nA 1.2 MB document of alternating text segments and apostrophes takes 34.9 seconds to convert, against 0.069 seconds for the same input with the extension not registered.\n\nHardened configuration makes this *worse* rather than better: `QuoteParser` appends the `Quote` node to the AST before pushing it onto the delimiter stack, so `max_delimiters_per_line` removes the quote-pairing work while leaving every node the listener must process.\n\n**2. `AttributesExtension` \u2014 block-level attribute runs re-scan their siblings (affected from 1.5.0).**\n\n`AttributesListener::findTargetAndDirection()` walks the entire remaining sibling chain for every block-level `Attributes` node whose target is the following node. The backward half of that walk returns immediately for such nodes, and the forward half stops only at a sibling that is not itself an attributes node \u2014 which a contiguous run never provides \u2014 so a run of k nodes costs k(k-1)/2 steps.\n\nAn input placing each `{#a}` on its own line, with a single reference definition to keep the run contiguous, takes 28.4 seconds at 16,000 attribute blocks while producing **zero bytes of output**.\n\nThis is the block-level counterpart of GHSA-g2gp-3wwq-f4ph, patched in 2.9.0. **That fix is incomplete:** the early break it introduced is guarded on the node being an `AttributesInline`, so block-level `Attributes` nodes still re-scan. Applications that upgraded to 2.9.0 specifically to address GHSA-g2gp-3wwq-f4ph remain exposed to this variant.\n\n**3. `AttributesExtension` \u2014 class lists are rebuilt on every merge (affected from 1.5.0).**\n\n`AttributesHelper::mergeAttributes()` round-trips the accumulated class list through `explode` and `implode` on each merge. An `#id` attribute assigns a scalar and skips the branch entirely, but a `.class` attribute appends to an array which is then imploded to a string, written to the target node, and read back on the next iteration \u2014 so the *i*th merge pays a cost proportional to *i* three separate times.\n\n`{.c}` repeated 32,000 times takes 33.5 seconds, against 0.26 seconds for byte-identical input using `{#a}` \u2014 a 130x gap that widens with input size. Both the inline and the block-level attribute paths are affected.\n\n**Overall impact.** An unauthenticated attacker who can submit Markdown to an affected application can consume disproportionate CPU time with a comparatively small request, occupying PHP workers and preventing legitimate requests from completing. The impact is limited to availability: no data is disclosed, rendered output is unchanged, and no rendering restriction is bypassed.\n\nNo library-level configuration gates any of these paths. For the Attributes extension in particular, neither the `attributes/allow` allow-list nor the `on*` event-handler hardening added in 2.7.0 has any effect, because the expensive work happens while parsing and resolving the AST, before any attribute filtering or rendering takes place.\n\n### Patches\n\nThe issues are patched in `2.9.1` and later:\n\n- Adjacent text merging now appends in place instead of reading, modifying, and writing back the whole literal, so a merge costs only the bytes added. This fixes the defect for every caller, not only the SmartPunct listener.\n- `AttributesListener` now records the runs it has already walked, so each contiguous run of block-level attribute nodes is scanned once rather than once per node.\n- Accumulated class lists no longer pass through `mergeAttributes()` repeatedly; the listener holds pending attributes and joins them in a single pass.\n\nThe SmartPunct path affects `2.0.0` through `2.9.0`. The Attributes paths affect `1.5.0` through `2.9.0`, including releases that already contain the 2.9.0 fix for GHSA-g2gp-3wwq-f4ph. The 1.x release line is no longer supported, so its users must upgrade to `2.9.1` or later.\n\n### Workarounds\n\nIf you cannot upgrade immediately:\n\n- **Do not register `SmartPunctExtension` or `AttributesExtension`** when converting untrusted Markdown. This fully removes the affected paths.\n- If either extension is required, **impose a strict maximum input length before conversion**. Because the cost is quadratic, even a modest cap must be small to meaningfully bound worst-case CPU time.\n\nRestricting conversion to trusted users, applying strict execution-time limits, and rate-limiting requests reduce exposure but are not substitutes for upgrading. Configuration options including `attributes/allow`, `max_delimiters_per_line`, `max_nesting_level`, `html_input`, and `allow_unsafe_links` do not mitigate these issues.",
  "id": "GHSA-jjv6-8j6v-6j52",
  "modified": "2026-09-01T20:21:45Z",
  "published": "2026-09-01T20:21:45Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/thephpleague/commonmark/security/advisories/GHSA-jjv6-8j6v-6j52"
    },
    {
      "type": "WEB",
      "url": "https://github.com/thephpleague/commonmark/commit/04a5d11ef6bf2d0b927310810d6a2a85d3c184b9"
    },
    {
      "type": "WEB",
      "url": "https://github.com/thephpleague/commonmark/commit/2f611b599c51661b005dc45c16ceaa547546e687"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/thephpleague/commonmark"
    },
    {
      "type": "WEB",
      "url": "https://github.com/thephpleague/commonmark/releases/tag/2.9.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "league/commonmark: Denial of service in the SmartPunct and Attributes extensions"
}

GHSA-JRM6-H9CQ-8GQW

Vulnerability from github – Published: 2023-06-30 22:17 – Updated: 2023-06-30 22:17

Summary

PyPDF2 quadratic runtime with malformed PDF missing xref marker

Details

Impact

An attacker who uses this vulnerability can craft a PDF which leads to unexpected long runtime. This quadratic runtime blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage.

Patches

https://github.com/py-pdf/pypdf/pull/808

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

References

Severity

6.2 (Medium)


                  
                    CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.27.8"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "PyPDF2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.27.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-36810"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-407"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-06-30T22:17:52Z",
    "nvd_published_at": "2023-06-30T19:15:09Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\nAn attacker who uses this vulnerability can craft a PDF which leads to unexpected long runtime.\nThis quadratic runtime blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage.\n\n### Patches\nhttps://github.com/py-pdf/pypdf/pull/808\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\n### References\n* [PyPDF2 PR #808](https://github.com/py-pdf/pypdf/pull/808)\n* [PyPDF2 Issue #582](https://github.com/py-pdf/pypdf/issues/582)",
  "id": "GHSA-jrm6-h9cq-8gqw",
  "modified": "2023-06-30T22:17:52Z",
  "published": "2023-06-30T22:17:52Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/security/advisories/GHSA-jrm6-h9cq-8gqw"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-36810"
    },
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/issues/582"
    },
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/pull/808"
    },
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/commit/c6c56f550bb384e05f0139c796ba1308837d6373"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/py-pdf/pypdf"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2023/07/msg00019.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "PyPDF2 quadratic runtime with malformed PDF missing xref marker"
}

GHSA-M3RP-25VQ-JFCV

Vulnerability from github – Published: 2026-08-18 15:31 – Updated: 2026-08-18 15:31

Details

Expat through 2.8.3 contains a denial of service vulnerability caused by quadratic algorithmic complexity in the storeAtts() function in xmlparse.c, where processing N specified attributes with non-normalized values triggers an O(N^2) linear scan of elementType->defaultAtts to determine CDATA status. A remote unauthenticated attacker can supply a single well-formed XML document of a few megabytes to an application parsing untrusted XML to cause excessive CPU consumption, resulting in denial of service without requiring authentication, external entity resolution, or non-default parser options.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

8.7 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-66046"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-407"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-18T15:16:57Z",
    "severity": "HIGH"
  },
  "details": "Expat through 2.8.3 contains a denial of service vulnerability caused by quadratic algorithmic complexity in the storeAtts() function in xmlparse.c, where processing N specified attributes with non-normalized values triggers an O(N^2) linear scan of elementType-\u003edefaultAtts to determine CDATA status. A remote unauthenticated attacker can supply a single well-formed XML document of a few megabytes to an application parsing untrusted XML to cause excessive CPU consumption, resulting in denial of service without requiring authentication, external entity resolution, or non-default parser options.",
  "id": "GHSA-m3rp-25vq-jfcv",
  "modified": "2026-08-18T15:31:47Z",
  "published": "2026-08-18T15:31:47Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-66046"
    },
    {
      "type": "WEB",
      "url": "https://github.com/libexpat/libexpat/pull/1321"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/expat-denial-of-service-via-storeatts-quadratic-complexity"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

GHSA-M54Q-MM9W-FP6G

Vulnerability from github – Published: 2025-08-29 14:59 – Updated: 2025-08-29 21:04

Summary

Exiv2 has quadratic performance in ICC profile parsing in JpegBase::readMetadata

Details

Impact

A denial-of-service was found in Exiv2 version v0.28.5: a quadratic algorithm in the ICC profile parsing code in jpegBase::readMetadata() can cause Exiv2 to run for a long time. Exiv2 is a command-line utility and C++ library for reading, writing, deleting, and modifying the metadata of image files. The denial-of-service is triggered when Exiv2 is used to read the metadata of a crafted jpg image file.

Patches

The bug is fixed in version v0.28.6.

References

Issue: https://github.com/Exiv2/exiv2/issues/3333 Fixes: https://github.com/Exiv2/exiv2/pull/3335 (main branch), https://github.com/Exiv2/exiv2/pull/3345 (0.28.x branch)

For more information

Please see our security policy for information about Exiv2 security.

Severity

1.8 (Low)


                  
                    CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "Exiv2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "0.17.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-55304"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-407"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-08-29T14:59:37Z",
    "nvd_published_at": "2025-08-29T15:15:35Z",
    "severity": "LOW"
  },
  "details": "### Impact\nA denial-of-service was found in Exiv2 version v0.28.5: a quadratic algorithm in the ICC profile parsing code in `jpegBase::readMetadata()` can cause Exiv2 to run for a long time. Exiv2 is a command-line utility and C++ library for reading, writing, deleting, and modifying the metadata of image files. The denial-of-service is triggered when Exiv2 is used to read the metadata of a crafted jpg image file.\n\n### Patches\nThe bug is fixed in version v0.28.6.\n\n### References\nIssue: https://github.com/Exiv2/exiv2/issues/3333\nFixes: https://github.com/Exiv2/exiv2/pull/3335 (main branch), https://github.com/Exiv2/exiv2/pull/3345 (0.28.x branch)\n\n### For more information\nPlease see our [security policy](https://github.com/Exiv2/exiv2/security/policy) for information about Exiv2 security.",
  "id": "GHSA-m54q-mm9w-fp6g",
  "modified": "2025-08-29T21:04:02Z",
  "published": "2025-08-29T14:59:37Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/Exiv2/exiv2/security/advisories/GHSA-m54q-mm9w-fp6g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-55304"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Exiv2/exiv2/issues/3333"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Exiv2/exiv2/pull/3335"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Exiv2/exiv2/pull/3345"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/Exiv2/exiv2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Exiv2 has quadratic performance in ICC profile parsing in JpegBase::readMetadata"
}

GHSA-M6HH-VP2V-RM5M

Vulnerability from github – Published: 2025-02-20 03:32 – Updated: 2025-02-20 03:32

Details

The hash table used to manage connections in picoquic before b80fd3f uses a weak hash function, allowing remote attackers to cause a considerable CPU load on the server (a Hash DoS attack) by initiating connections with colliding Source Connection IDs (SCIDs).

Severity

5.3 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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{
  "affected": [],
  "aliases": [
    "CVE-2025-24946"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-407"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-02-20T03:15:12Z",
    "severity": "MODERATE"
  },
  "details": "The hash table used to manage connections in picoquic before b80fd3f uses a weak hash function, allowing remote attackers to cause a considerable CPU load on the server (a Hash DoS attack) by initiating connections with colliding Source Connection IDs (SCIDs).",
  "id": "GHSA-m6hh-vp2v-rm5m",
  "modified": "2025-02-20T03:32:03Z",
  "published": "2025-02-20T03:32:03Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-24946"
    },
    {
      "type": "WEB",
      "url": "https://github.com/private-octopus/picoquic/commit/b80fd3f5903279ae3e7714ee4109363d9ab4491a"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ncc-pbottine/QUIC-Hash-Dos-Advisory"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-MFJ6-6P54-M98C

Vulnerability from github – Published: 2026-03-31 23:49 – Updated: 2026-03-31 23:49

Summary

parse-server has GraphQL complexity validator exponential fragment traversal DoS

Details

Impact

The GraphQL query complexity validator can be exploited to cause a denial-of-service by sending a crafted query with binary fan-out fragment spreads. A single unauthenticated request can block the Node.js event loop for seconds, denying service to all concurrent users. This only affects deployments that have enabled the requestComplexity.graphQLDepth or requestComplexity.graphQLFields configuration options.

Patches

The fix replaces the per-branch fragment traversal with memoized fragment computation, reducing the traversal from exponential O(2^N) to linear O(N) time. Additionally, early termination aborts the traversal as soon as configured limits are exceeded.

Workarounds

Disable GraphQL complexity limits by setting requestComplexity.graphQLDepth and requestComplexity.graphQLFields to -1 (the default).

Resources

GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-mfj6-6p54-m98c
Fix Parse Server 9: https://github.com/parse-community/parse-server/pull/10344
Fix Parse Server 8: https://github.com/parse-community/parse-server/pull/10345

Severity

8.2 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "parse-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "9.0.0"
            },
            {
              "fixed": "9.7.0-alpha.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "parse-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.6.68"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-34573"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-407"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-31T23:49:18Z",
    "nvd_published_at": "2026-03-31T16:16:33Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nThe GraphQL query complexity validator can be exploited to cause a denial-of-service by sending a crafted query with binary fan-out fragment spreads. A single unauthenticated request can block the Node.js event loop for seconds, denying service to all concurrent users. This only affects deployments that have enabled the `requestComplexity.graphQLDepth` or `requestComplexity.graphQLFields` configuration options.\n\n### Patches\n\nThe fix replaces the per-branch fragment traversal with memoized fragment computation, reducing the traversal from exponential O(2^N) to linear O(N) time. Additionally, early termination aborts the traversal as soon as configured limits are exceeded.\n\n### Workarounds\n\nDisable GraphQL complexity limits by setting `requestComplexity.graphQLDepth` and `requestComplexity.graphQLFields` to `-1` (the default).\n\n### Resources\n\n- GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-mfj6-6p54-m98c\n- Fix Parse Server 9: https://github.com/parse-community/parse-server/pull/10344\n- Fix Parse Server 8: https://github.com/parse-community/parse-server/pull/10345",
  "id": "GHSA-mfj6-6p54-m98c",
  "modified": "2026-03-31T23:49:18Z",
  "published": "2026-03-31T23:49:18Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/parse-community/parse-server/security/advisories/GHSA-mfj6-6p54-m98c"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34573"
    },
    {
      "type": "WEB",
      "url": "https://github.com/parse-community/parse-server/pull/10344"
    },
    {
      "type": "WEB",
      "url": "https://github.com/parse-community/parse-server/pull/10345"
    },
    {
      "type": "WEB",
      "url": "https://github.com/parse-community/parse-server/commit/ea15412795f34594cc8a674fe858d445675e0295"
    },
    {
      "type": "WEB",
      "url": "https://github.com/parse-community/parse-server/commit/f759bda075298ec44e2b4fb57659a0c56620483b"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/parse-community/parse-server"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "parse-server has GraphQL complexity validator exponential fragment traversal DoS"
}

GHSA-MFV9-QX66-GXM4

Vulnerability from github – Published: 2026-09-14 12:31 – Updated: 2026-09-14 12:31

Details

Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to parse Markdown autolinks with unmatched trailing closing parentheses in linear time, which allows an authenticated user with permission to create posts to cause excessive server CPU consumption and degrade availability for other users via specially crafted post or message attachment content. Mattermost Advisory ID: MMSA-2026-00703

Severity

4.3 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

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{
  "affected": [],
  "aliases": [
    "CVE-2026-12882"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-407"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-14T11:17:03Z",
    "severity": "MODERATE"
  },
  "details": "Mattermost versions 11.9.x \u003c= 11.9.0, 11.8.x \u003c= 11.8.4, 11.7.x \u003c= 11.7.7, 10.11.x \u003c= 10.11.22 fail to parse Markdown autolinks with unmatched trailing closing parentheses in linear time, which allows an authenticated user with permission to create posts to cause excessive server CPU consumption and degrade availability for other users via specially crafted post or message attachment content. Mattermost Advisory ID: MMSA-2026-00703",
  "id": "GHSA-mfv9-qx66-gxm4",
  "modified": "2026-09-14T12:31:37Z",
  "published": "2026-09-14T12:31:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-12882"
    },
    {
      "type": "WEB",
      "url": "https://mattermost.com/security-updates"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-MH25-X5HQ-WRQP

Vulnerability from github – Published: 2026-08-06 20:41 – Updated: 2026-08-06 20:41

Summary

league/commonmark: Denial of service via colliding heading slugs

Details

Impact

UniqueSlugNormalizer::normalize() makes each slug document-unique by searching for an unused numeric suffix, but restarts that search from 1 on every collision. The k-th heading that collapses to the same base slug performs k−1 array lookups, so K colliding slugs cost Σ(k−1) = O(K²). An attacker can force every heading onto a single base slug trivially — many empty ATX headings, identical heading text, or punctuation-only headings that normalize to the empty string.

The path is reached whenever the shared slug normalizer runs over attacker-controlled text. That happens when HeadingPermalinkExtension is registered (its HeadingPermalinkProcessor normalizes every heading), independently through FootnoteExtension (its AnonymousFootnoteRefParser normalizes every ^[label] reference), and on any TableOfContentsExtension site (which requires HeadingPermalinkExtension to be co-registered). The default slug_normalizer/unique setting (UniqueSlugNormalizerInterface::PER_DOCUMENT) accumulates collisions across the whole document. No authentication is required — a small document body turns into seconds of CPU and denies service. Availability impact only. UniqueSlugNormalizer was introduced in 2.0.0 (first shipped in 2.0.0-beta1, May 2021); the 1.x heading-permalink slug generator performed no de-duplication and is not affected. All 2.x releases (including 2.8.x) are affected.

Workarounds

Integrators who cannot upgrade immediately can:

Set slug_normalizer/unique to false / UniqueSlugNormalizerInterface::DISABLED, which stops the de-duplication scan entirely — at the cost of losing id uniqueness (colliding headings then share an anchor).
Disable HeadingPermalinkExtension (and TableOfContentsExtension, which depends on it), and FootnoteExtension where anonymous footnotes reach the same normalizer, for untrusted Markdown.
Cap the accepted document size / heading count upstream so K cannot reach the quadratic danger zone.

Each of these trades off functionality or correctness; upgrading to the patched release (which removes the quadratic behavior while keeping unique ids and identical output) is the recommended remediation.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "league/commonmark"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0"
            },
            {
              "fixed": "2.9.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-407"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-08-06T20:41:45Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Impact\n\n`UniqueSlugNormalizer::normalize()` makes each slug document-unique by searching for an unused numeric suffix, but **restarts that search from `1` on every collision**. The k-th heading that collapses to the same base slug performs k\u22121 array lookups, so K colliding slugs cost \u03a3(k\u22121) = **O(K\u00b2)**. An attacker can force every heading onto a single base slug trivially \u2014 many empty ATX headings, identical heading text, or punctuation-only headings that normalize to the empty string.\n\nThe path is reached whenever the shared slug normalizer runs over attacker-controlled text. That happens when `HeadingPermalinkExtension` is registered (its `HeadingPermalinkProcessor` normalizes every heading), independently through `FootnoteExtension` (its `AnonymousFootnoteRefParser` normalizes every `^[label]` reference), and on any `TableOfContentsExtension` site (which requires `HeadingPermalinkExtension` to be co-registered). The default `slug_normalizer/unique` setting (`UniqueSlugNormalizerInterface::PER_DOCUMENT`) accumulates collisions across the whole document. No authentication is required \u2014 a small document body turns into seconds of CPU and denies service. Availability impact only. **`UniqueSlugNormalizer` was introduced in 2.0.0 (first shipped in 2.0.0-beta1, May 2021); the 1.x heading-permalink slug generator performed no de-duplication and is not affected. All 2.x releases (including 2.8.x) are affected.**\n\n### Workarounds\n\nIntegrators who cannot upgrade immediately can:\n\n- **Set `slug_normalizer/unique` to `false` / `UniqueSlugNormalizerInterface::DISABLED`**, which stops the de-duplication scan entirely \u2014 at the cost of losing id uniqueness (colliding headings then share an anchor).\n- **Disable `HeadingPermalinkExtension`** (and `TableOfContentsExtension`, which depends on it), and `FootnoteExtension` where anonymous footnotes reach the same normalizer, for untrusted Markdown.\n- **Cap the accepted document size / heading count upstream** so K cannot reach the quadratic danger zone.\n\nEach of these trades off functionality or correctness; upgrading to the patched release (which removes the quadratic behavior while keeping unique ids and identical output) is the recommended remediation.",
  "id": "GHSA-mh25-x5hq-wrqp",
  "modified": "2026-08-06T20:41:45Z",
  "published": "2026-08-06T20:41:45Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/thephpleague/commonmark/security/advisories/GHSA-mh25-x5hq-wrqp"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/thephpleague/commonmark"
    },
    {
      "type": "WEB",
      "url": "https://github.com/thephpleague/commonmark/releases/tag/2.9.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "league/commonmark: Denial of service via colliding heading slugs"
}

GHSA-MVMF-94V6-879G

Vulnerability from github – Published: 2026-06-30 15:30 – Updated: 2026-07-02 21:32

Details

fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen mode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n²)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.This allows a single malicious request to monopolize the single‑threaded HTTP server, blocking all other clients and resulting in denial of service.

This issue was fixed in version 0.73.1.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

5.7 (Medium)


                  
                    CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-53433"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-407"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-30T13:19:13Z",
    "severity": "MODERATE"
  },
  "details": "fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen mode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n\u00b2)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.This allows a single malicious request to monopolize the single\u2011threaded HTTP server, blocking all other clients and resulting in denial of service.\n\nThis issue was fixed in version 0.73.1.",
  "id": "GHSA-mvmf-94v6-879g",
  "modified": "2026-07-02T21:32:10Z",
  "published": "2026-06-30T15:30:44Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53433"
    },
    {
      "type": "WEB",
      "url": "https://github.com/junegunn/fzf/commit/7963a2c6586c0b9eaa89b8995de8f0e08cf8a4ce"
    },
    {
      "type": "WEB",
      "url": "https://cert.pl/en/posts/2026/06/CVE-2026-53432"
    },
    {
      "type": "WEB",
      "url": "https://github.com/junegunn/fzf"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

GHSA-PM4M-PH32-GHV5

Vulnerability from github – Published: 2026-07-24 16:47 – Updated: 2026-08-13 17:47

Summary

js-yaml: Exponential parsing time in flow collections leads to denial of service

Details

Summary

Parsing a small YAML document can take exponential time. An application that calls load() or loadAll() on untrusted input can be hung by a payload under 200 bytes.

Details

When an entry in a flow sequence turns out to be a key: value pair, the parser rewinds and parses that entry a second time as the key. If the key is itself a nested flow sequence of the same shape, every level is parsed twice, so the total work is O(2^n) in the nesting depth. The default maxDepth of 100 does not help, because the time is already unmanageable at about 30 to 40 levels.

Root cause, potentially the: readFlowCollection in parser.ts, the restoreState followed by a second parseNode further down.

PoC

const yaml = require('js-yaml')
const n = 30
yaml.load('[ '.repeat(n) + '1' + ' ]: 0'.repeat(n))

With default options: 22 levels takes about 1 second, 26 levels about 17 seconds, 30 levels over 2 minutes. The input stays under 200 bytes and grows linearly with n.

Impact

Denial of service. A single small request can keep one CPU busy for minutes or longer and blocks the Node event loop, so one request can stall the whole process. No anchors, aliases, merges, tags, or non default options are required, and it reproduces on the default schema.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 5.2.1"
      },
      "package": {
        "ecosystem": "npm",
        "name": "js-yaml"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.0.0"
            },
            {
              "fixed": "5.2.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-73643"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-407"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-24T16:47:36Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\nParsing a small YAML document can take exponential time. An application that calls `load()` or `loadAll()` on untrusted input can be hung by a payload under 200 bytes.\n\n### Details\nWhen an entry in a flow sequence turns out to be a `key: value` pair, the parser rewinds and parses that entry a second time as the key.\nIf the key is itself a nested flow sequence of the same shape, every level is parsed twice, so the total work is O(2^n) in the nesting depth. The default `maxDepth` of 100 does not help, because the time is already unmanageable at about 30 to 40 levels.\n\nRoot cause, potentially the: `readFlowCollection` in [parser.ts](https://github.com/nodeca/js-yaml/blob/master/src/parser/parser.ts), the `restoreState` followed by a second `parseNode` further down.\n\n\n### PoC\n\n```javascript\nconst yaml = require(\u0027js-yaml\u0027)\nconst n = 30\nyaml.load(\u0027[ \u0027.repeat(n) + \u00271\u0027 + \u0027 ]: 0\u0027.repeat(n))\n```\n\nWith default options: 22 levels takes about 1 second, 26 levels about 17 seconds, 30 levels over 2 minutes. The input stays under 200 bytes and grows linearly with `n`.\n\n### Impact\nDenial of service. A single small request can keep one CPU busy for minutes or longer and blocks the Node event loop, so one request can stall the whole process. No anchors, aliases, merges, tags, or non default options are required, and it reproduces on the default schema.",
  "id": "GHSA-pm4m-ph32-ghv5",
  "modified": "2026-08-13T17:47:36Z",
  "published": "2026-07-24T16:47:36Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nodeca/js-yaml/security/advisories/GHSA-pm4m-ph32-ghv5"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodeca/js-yaml/commit/3e5240f9cbe645ce5afb58524954a13c8539c853"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/nodeca/js-yaml"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodeca/js-yaml/releases/tag/5.2.2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "js-yaml: Exponential parsing time in flow collections leads to denial of service"
}

CWE-407

Inefficient Algorithmic Complexity

Impact

Patches

Workarounds

Impact

Patches

Workarounds

References

Impact

Patches

References

For more information

Impact

Patches

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Resources

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Summary

Details

PoC

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