Common Weakness Enumeration

CWE-674

Allowed-with-Review

Uncontrolled Recursion

Abstraction: Class · Status: Draft

API response cwe.mitre.org

The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.

744 vulnerabilities reference this CWE, most recent first.

GHSA-V43P-PV9W-GQMF

Vulnerability from github – Published: 2026-02-21 21:30 – Updated: 2026-02-21 21:30
VLAI
Details

A security vulnerability has been detected in aardappel lobster up to 2025.4. This impacts the function lobster::TypeName in the library dev/src/lobster/idents.h. Such manipulation leads to uncontrolled recursion. The attack can only be performed from a local environment. The exploit has been disclosed publicly and may be used. Upgrading to version 2026.1 will fix this issue. The name of the patch is 8ba49f98ccfc9734ef352146806433a41d9f9aa6. It is advisable to upgrade the affected component.

Severity
3.3 (Low)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
1.9 (Low)
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
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{
  "affected": [],
  "aliases": [
    "CVE-2026-2887"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-404",
      "CWE-674"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-02-21T21:16:11Z",
    "severity": "MODERATE"
  },
  "details": "A security vulnerability has been detected in aardappel lobster up to 2025.4. This impacts the function lobster::TypeName in the library dev/src/lobster/idents.h. Such manipulation leads to uncontrolled recursion. The attack can only be performed from a local environment. The exploit has been disclosed publicly and may be used. Upgrading to version 2026.1 will fix this issue. The name of the patch is 8ba49f98ccfc9734ef352146806433a41d9f9aa6. It is advisable to upgrade the affected component.",
  "id": "GHSA-v43p-pv9w-gqmf",
  "modified": "2026-02-21T21:30:27Z",
  "published": "2026-02-21T21:30:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-2887"
    },
    {
      "type": "WEB",
      "url": "https://github.com/aardappel/lobster/issues/397"
    },
    {
      "type": "WEB",
      "url": "https://github.com/aardappel/lobster/issues/397#issuecomment-3849015088"
    },
    {
      "type": "WEB",
      "url": "https://github.com/aardappel/lobster/commit/8ba49f98ccfc9734ef352146806433a41d9f9aa6"
    },
    {
      "type": "WEB",
      "url": "https://github.com/aardappel/lobster"
    },
    {
      "type": "WEB",
      "url": "https://github.com/aardappel/lobster/releases/tag/v2026.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/oneafter/0204/blob/main/lob3/repro.lobster"
    },
    {
      "type": "WEB",
      "url": "https://vuldb.com/?ctiid.347181"
    },
    {
      "type": "WEB",
      "url": "https://vuldb.com/?id.347181"
    },
    {
      "type": "WEB",
      "url": "https://vuldb.com/?submit.755026"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/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-V5PM-XWQC-G5WC

Vulnerability from github – Published: 2026-06-30 15:56 – Updated: 2026-07-06 12:57
VLAI
Summary
Microsoft.OpenAPI: Circular schema references may terminate OpenAPI parsing
Details

Impact

A small OpenAPI document containing a circular schema reference can cause process termination through stack overflow in Microsoft.OpenApi. The issue affects OpenAPI document parsing through public OpenAPI.NET reader APIs and has been confirmed across both JSON and YAML reader paths.

Affected versions

  • >= 2.0.0-preview.11, <= 2.7.4
  • >= 3.0.0, <= 3.5.3

Patches

  • For the 2.X major version, versions 2.7.5 and above are patched.
  • For the 3.X major version, versions 3.5.4 and above are patched.
  • For the 1.X major version, the issue does not apply since that version of the library could not resolve references that pointed to another reference.

Impact

Applications, CLIs, developer tools, or services that parse untrusted OpenAPI documents in-process may be terminated by a crafted OpenAPI document containing circular schema references.

The impact is availability/process termination only. This report does not claim remote code execution, authentication bypass, credential exposure, privilege escalation, data exposure, or Microsoft hosted service impact.

Details

A standalone isolated-process harness confirmed repeatable process termination through public OpenAPI.NET reader APIs. The issue reproduces in the affected released NuGet packages and affects both JSON and YAML reader paths.

A separate Microsoft-owned local consumer, microsoft/kiota, also reproduces the termination through the kiota show --openapi <file> workflow. That workflow parses OpenAPI files in-process using Microsoft.OpenApi and Microsoft.OpenApi.YamlReader.

Example payload

{
    "openapi": "3.0.0",
    "info": {
        "title": "Test",
        "version": "0.0.1"
    },
    "paths": {},
    "components": {
        "schemas": {
            "A": {
                "$ref": "#/components/schemas/B"
            },
            "B": {
                "$ref": "#/components/schemas/A"
            }
        }
    }
}

Remediation

Users should upgrade to Microsoft.OpenApi 2.7.5 or 3.5.4, depending on the major version line they consume.

Applications that parse OpenAPI documents from untrusted sources should avoid parsing those documents in the primary application process when possible. Running parsing in an isolated process can reduce the blast radius of parser failures.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Show details on source website
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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.7.4"
      },
      "package": {
        "ecosystem": "NuGet",
        "name": "Microsoft.OpenApi"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0-preview.11"
            },
            {
              "fixed": "2.7.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 3.5.3"
      },
      "package": {
        "ecosystem": "NuGet",
        "name": "Microsoft.OpenApi"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.0.0"
            },
            {
              "fixed": "3.5.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-49451"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-674"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-30T15:56:24Z",
    "nvd_published_at": "2026-06-30T17:16:22Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nA small OpenAPI document containing a circular schema reference can cause process termination through stack overflow in Microsoft.OpenApi. The issue affects OpenAPI document parsing through public OpenAPI.NET reader APIs and has been confirmed across both JSON and YAML reader paths.\n\n## Affected versions\n\n- `\u003e= 2.0.0-preview.11, \u003c= 2.7.4`\n- `\u003e= 3.0.0, \u003c= 3.5.3`\n\n### Patches\n\n- For the 2.X major version, versions 2.7.5 and above are patched.\n- For the 3.X major version, versions 3.5.4 and above are patched.\n- For the 1.X major version, the issue does not apply since that version of the library *could not* resolve references that pointed to another reference.\n\n## Impact\n\nApplications, CLIs, developer tools, or services that parse untrusted OpenAPI documents in-process may be terminated by a crafted OpenAPI document containing circular schema references.\n\nThe impact is availability/process termination only. This report does not claim remote code execution, authentication bypass, credential exposure, privilege escalation, data exposure, or Microsoft hosted service impact.\n\n## Details\n\nA standalone isolated-process harness confirmed repeatable process termination through public OpenAPI.NET reader APIs. The issue reproduces in the affected released NuGet packages and affects both JSON and YAML reader paths.\n\nA separate Microsoft-owned local consumer, `microsoft/kiota`, also reproduces the termination through the `kiota show --openapi \u003cfile\u003e` workflow. That workflow parses OpenAPI files in-process using Microsoft.OpenApi and Microsoft.OpenApi.YamlReader.\n\n### Example payload\n\n```json\n{\n    \"openapi\": \"3.0.0\",\n    \"info\": {\n        \"title\": \"Test\",\n        \"version\": \"0.0.1\"\n    },\n    \"paths\": {},\n    \"components\": {\n        \"schemas\": {\n            \"A\": {\n                \"$ref\": \"#/components/schemas/B\"\n            },\n            \"B\": {\n                \"$ref\": \"#/components/schemas/A\"\n            }\n        }\n    }\n}\n```\n\n## Remediation\n\nUsers should upgrade to Microsoft.OpenApi `2.7.5` or `3.5.4`, depending on the major version line they consume.\n\nApplications that parse OpenAPI documents from untrusted sources should avoid parsing those documents in the primary application process when possible. Running parsing in an isolated process can reduce the blast radius of parser failures.",
  "id": "GHSA-v5pm-xwqc-g5wc",
  "modified": "2026-07-06T12:57:29Z",
  "published": "2026-06-30T15:56:24Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/microsoft/OpenAPI.NET/security/advisories/GHSA-v5pm-xwqc-g5wc"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-49451"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/microsoft/OpenAPI.NET"
    }
  ],
  "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": "Microsoft.OpenAPI: Circular schema references may terminate OpenAPI parsing"
}

GHSA-V5RQ-2Q5P-P82V

Vulnerability from github – Published: 2022-05-13 01:23 – Updated: 2024-03-21 03:33
VLAI
Details

** DISPUTED ** In the GNU C Library (aka glibc or libc6) through 2.29, check_dst_limits_calc_pos_1 in posix/regexec.c has Uncontrolled Recursion, as demonstrated by '(|)(\1\1)*' in grep, a different issue than CVE-2018-20796. NOTE: the software maintainer disputes that this is a vulnerability because the behavior occurs only with a crafted pattern.

Severity
7.5 (High)
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Show details on source website
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{
  "affected": [],
  "aliases": [
    "CVE-2019-9192"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-674"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2019-02-26T18:29:00Z",
    "severity": "HIGH"
  },
  "details": "** DISPUTED ** In the GNU C Library (aka glibc or libc6) through 2.29, check_dst_limits_calc_pos_1 in posix/regexec.c has Uncontrolled Recursion, as demonstrated by \u0027(|)(\\\\1\\\\1)*\u0027 in grep, a different issue than CVE-2018-20796. NOTE: the software maintainer disputes that this is a vulnerability because the behavior occurs only with a crafted pattern.",
  "id": "GHSA-v5rq-2q5p-p82v",
  "modified": "2024-03-21T03:33:33Z",
  "published": "2022-05-13T01:23:03Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2019-9192"
    },
    {
      "type": "WEB",
      "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=24269"
    },
    {
      "type": "WEB",
      "url": "https://support.f5.com/csp/article/K26346590?utm_source=f5support\u0026amp%3Butm_medium=RSS"
    },
    {
      "type": "WEB",
      "url": "https://support.f5.com/csp/article/K26346590?utm_source=f5support\u0026amp;utm_medium=RSS"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-V6W7-GQ3G-FWVM

Vulnerability from github – Published: 2022-05-24 17:43 – Updated: 2022-06-04 00:00
VLAI
Details

A stack overflow via an infinite recursion vulnerability was found in the eepro100 i8255x device emulator of QEMU. This issue occurs while processing controller commands due to a DMA reentry issue. This flaw allows a guest user or process to consume CPU cycles or crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2021-20255"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-674",
      "CWE-835"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2021-03-09T20:15:00Z",
    "severity": "MODERATE"
  },
  "details": "A stack overflow via an infinite recursion vulnerability was found in the eepro100 i8255x device emulator of QEMU. This issue occurs while processing controller commands due to a DMA reentry issue. This flaw allows a guest user or process to consume CPU cycles or crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.",
  "id": "GHSA-v6w7-gq3g-fwvm",
  "modified": "2022-06-04T00:00:55Z",
  "published": "2022-05-24T17:43:53Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-20255"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1930646"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2021/04/msg00009.html"
    },
    {
      "type": "WEB",
      "url": "https://ruhr-uni-bochum.sciebo.de/s/NNWP2GfwzYKeKwE?path=%2Feepro100_stackoverflow1"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20210507-0003"
    },
    {
      "type": "WEB",
      "url": "https://www.openwall.com/lists/oss-security/2021/02/25/1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-V78M-2Q7V-FJQP

Vulnerability from github – Published: 2022-06-22 17:52 – Updated: 2022-07-12 21:59
VLAI
Summary
Uncontrolled Recursion in rulex
Details

Impact

When parsing untrusted rulex expressions, the stack may overflow, possibly enabling a Denial of Service attack. This happens when parsing an expression with several hundred levels of nesting, causing the process to abort immediately.

This is a security concern for you, if - your service parses untrusted rulex expressions (expressions provided by an untrusted user), and - your service becomes unavailable when the process running rulex aborts due to a stack overflow.

Patches

The crash is fixed in version 0.4.3. Affected users are advised to update to this version.

Workarounds

None.

For more information

If you have any questions or comments about this advisory: * Open an issue in rulex * Email me at ludwig.stecher@gmx.de

Credits

Credit for finding these bugs goes to

Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "rulex"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.4.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2022-31099"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-674"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2022-06-22T17:52:51Z",
    "nvd_published_at": "2022-06-27T23:15:00Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\nWhen parsing untrusted rulex expressions, the stack may overflow, possibly enabling a Denial of Service attack. This happens when parsing an expression with several hundred levels of nesting, causing the process to abort immediately.\n\nThis is a security concern for you, if\n- your service parses untrusted rulex expressions (expressions provided by an untrusted user), and\n- your service becomes unavailable when the process running rulex aborts due to a stack overflow.\n\n### Patches\nThe crash is fixed in version **0.4.3**. Affected users are advised to update to this version.\n\n### Workarounds\nNone.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [rulex](https://github.com/rulex-rs/rulex/issues)\n* Email me at [ludwig.stecher@gmx.de](mailto:ludwig.stecher@gmx.de)\n\n### Credits\n\nCredit for finding these bugs goes to\n\n- [evanrichter](https://github.com/evanrichter)\n- [ForAllSecure Mayhem](https://forallsecure.com/)\n- [cargo fuzz](https://github.com/rust-fuzz/cargo-fuzz) and [afl.rs](https://github.com/rust-fuzz/afl.rs)",
  "id": "GHSA-v78m-2q7v-fjqp",
  "modified": "2022-07-12T21:59:11Z",
  "published": "2022-06-22T17:52:51Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/rulex-rs/rulex/security/advisories/GHSA-v78m-2q7v-fjqp"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-31099"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rulex-rs/rulex/commit/60aa2dc03a22d69c8800fec81f99c96958a11363"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/rulex-rs/rulex"
    },
    {
      "type": "WEB",
      "url": "https://rustsec.org/advisories/RUSTSEC-2022-0030.html"
    }
  ],
  "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:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Uncontrolled Recursion in rulex"
}

GHSA-V7CF-C9RM-WM3J

Vulnerability from github – Published: 2026-03-17 14:07 – Updated: 2026-08-25 16:40
VLAI
Summary
Uncontrolled recursion DoS in JustHTML() via deeply nested HTML
Details

Summary

justhtml through 1.9.1 allows denial of service via deeply nested HTML. During parsing, JustHTML.__init__() always reaches TreeBuilder.finish(), which unconditionally calls _populate_selectedcontent(). That function recursively traverses the DOM via _find_elements() / _find_element() without a depth bound, allowing attacker-controlled deeply nested input to trigger an unhandled RecursionError on CPython. Depending on the host application's exception handling, this can abort parsing, fail requests, or terminate a worker/process.

Details

TreeBuilder.finish() (treebuilder.py#L476) unconditionally calls _populate_selectedcontent(self.document) at line 494. _populate_selectedcontent() (treebuilder.py#L1243) calls _find_elements() (treebuilder.py#L1280) to recursively search the DOM tree for <select> elements:

def _find_elements(self, node: Any, name: str, result: list[Any]) -> None:
    """Recursively find all elements with given name."""
    if node.name == name:
        result.append(node)
    if node.has_child_nodes():
        for child in node.children:
            self._find_elements(child, name, result)  # recursive call

When the DOM tree depth exceeds CPython's default recursion limit (1000), this raises an unhandled RecursionError. The full call path is:

JustHTML(html) → tokenizer.run() → tree_builder.finish() → _populate_selectedcontent(document) → _find_elements(root, "select", selects) (recursive)

Deeply nested DOM trees can be produced by nesting <div> tags ~1000 levels deep. On CPython with the default recursion limit, approximately 11 KB of <div> nesting is sufficient to trigger the error. The exact depth threshold is environment-dependent (CPython version, recursion limit setting, call stack depth at invocation).

Additional recursive functions are affected on already-parsed deep trees: - Node.clone_node(deep=True) (node.py#L523) — called during sanitization - _node_to_html() (serialize.py#L580) — used by to_html(pretty=True) - _to_markdown_walk() (node.py#L817) — used by to_markdown()

Note: the library already uses iterative traversal in several comparable functions (e.g., _node_to_html_compact at serialize.py#L197, _to_text_collect at node.py#L161, _is_blocky_element at serialize.py#L405, apply_to_children at transforms.py#L1642), demonstrating the correct pattern.

PoC

from justhtml import JustHTML

html = "<div>" * 1000 + "x" + "</div>" * 1000
doc = JustHTML(html)  # raises RecursionError

Test environment: CPython 3.14.3, macOS ARM64 (Apple Silicon), justhtml 1.9.1, default recursion limit (1000)

Input Size Result
<div> × 500 5,501 bytes OK
<div> × 800 8,801 bytes OK
<div> × 1000 11,001 bytes RecursionError

The error occurs with both sanitize=True (default) and sanitize=False.

Impact

An attacker who can supply HTML for parsing can trigger an unhandled RecursionError during JustHTML() construction. The error is triggered during construction and is not avoided by justhtml configuration alone; mitigating it requires host-application exception handling or input constraints. Depending on the host application's exception handling, this can abort parsing, fail requests, or terminate a worker/process.

Suggested Fix

Convert the recursive tree traversal functions to iterative implementations using an explicit stack. Example for _find_elements:

def _find_elements(self, node: Any, name: str, result: list[Any]) -> None:
    stack = [node]
    while stack:
        current = stack.pop()
        if current.name == name:
            result.append(current)
        if current.has_child_nodes():
            stack.extend(reversed(current.children))

The same conversion should be applied to _find_element, clone_node(deep=True), _node_to_html(), and _to_markdown_walk().

Severity
7.1 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.9.1"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "justhtml"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.10.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-9769"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-674"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-17T14:07:38Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\n\njusthtml through 1.9.1 allows denial of service via deeply nested HTML. During parsing, `JustHTML.__init__()` always reaches `TreeBuilder.finish()`, which unconditionally calls `_populate_selectedcontent()`. That function recursively traverses the DOM via `_find_elements()` / `_find_element()` without a depth bound, allowing attacker-controlled deeply nested input to trigger an unhandled `RecursionError` on CPython. Depending on the host application\u0027s exception handling, this can abort parsing, fail requests, or terminate a worker/process.\n\n### Details\n\n`TreeBuilder.finish()` ([`treebuilder.py#L476`](https://github.com/EmilStenstrom/justhtml/blob/a866b6077770d9ec4cb6b6f9bfe7c918f98455e4/src/justhtml/treebuilder.py#L476)) unconditionally calls `_populate_selectedcontent(self.document)` at [line 494](https://github.com/EmilStenstrom/justhtml/blob/a866b6077770d9ec4cb6b6f9bfe7c918f98455e4/src/justhtml/treebuilder.py#L494). `_populate_selectedcontent()` ([`treebuilder.py#L1243`](https://github.com/EmilStenstrom/justhtml/blob/a866b6077770d9ec4cb6b6f9bfe7c918f98455e4/src/justhtml/treebuilder.py#L1243)) calls `_find_elements()` ([`treebuilder.py#L1280`](https://github.com/EmilStenstrom/justhtml/blob/a866b6077770d9ec4cb6b6f9bfe7c918f98455e4/src/justhtml/treebuilder.py#L1280)) to recursively search the DOM tree for `\u003cselect\u003e` elements:\n\n```python\ndef _find_elements(self, node: Any, name: str, result: list[Any]) -\u003e None:\n    \"\"\"Recursively find all elements with given name.\"\"\"\n    if node.name == name:\n        result.append(node)\n    if node.has_child_nodes():\n        for child in node.children:\n            self._find_elements(child, name, result)  # recursive call\n```\n\nWhen the DOM tree depth exceeds CPython\u0027s default recursion limit (1000), this raises an unhandled `RecursionError`. The full call path is:\n\n`JustHTML(html)` \u2192 `tokenizer.run()` \u2192 `tree_builder.finish()` \u2192 `_populate_selectedcontent(document)` \u2192 `_find_elements(root, \"select\", selects)` (recursive)\n\nDeeply nested DOM trees can be produced by nesting `\u003cdiv\u003e` tags ~1000 levels deep. On CPython with the default recursion limit, approximately 11 KB of `\u003cdiv\u003e` nesting is sufficient to trigger the error. The exact depth threshold is environment-dependent (CPython version, recursion limit setting, call stack depth at invocation).\n\nAdditional recursive functions are affected on already-parsed deep trees:\n- `Node.clone_node(deep=True)` ([`node.py#L523`](https://github.com/EmilStenstrom/justhtml/blob/a866b6077770d9ec4cb6b6f9bfe7c918f98455e4/src/justhtml/node.py#L523)) \u2014 called during sanitization\n- `_node_to_html()` ([`serialize.py#L580`](https://github.com/EmilStenstrom/justhtml/blob/a866b6077770d9ec4cb6b6f9bfe7c918f98455e4/src/justhtml/serialize.py#L580)) \u2014 used by `to_html(pretty=True)`\n- `_to_markdown_walk()` ([`node.py#L817`](https://github.com/EmilStenstrom/justhtml/blob/a866b6077770d9ec4cb6b6f9bfe7c918f98455e4/src/justhtml/node.py#L817)) \u2014 used by `to_markdown()`\n\nNote: the library already uses iterative traversal in several comparable functions (e.g., `_node_to_html_compact` at [`serialize.py#L197`](https://github.com/EmilStenstrom/justhtml/blob/a866b6077770d9ec4cb6b6f9bfe7c918f98455e4/src/justhtml/serialize.py#L197), `_to_text_collect` at [`node.py#L161`](https://github.com/EmilStenstrom/justhtml/blob/a866b6077770d9ec4cb6b6f9bfe7c918f98455e4/src/justhtml/node.py#L161), `_is_blocky_element` at [`serialize.py#L405`](https://github.com/EmilStenstrom/justhtml/blob/a866b6077770d9ec4cb6b6f9bfe7c918f98455e4/src/justhtml/serialize.py#L405), `apply_to_children` at [`transforms.py#L1642`](https://github.com/EmilStenstrom/justhtml/blob/a866b6077770d9ec4cb6b6f9bfe7c918f98455e4/src/justhtml/transforms.py#L1642)), demonstrating the correct pattern.\n\n### PoC\n\n```python\nfrom justhtml import JustHTML\n\nhtml = \"\u003cdiv\u003e\" * 1000 + \"x\" + \"\u003c/div\u003e\" * 1000\ndoc = JustHTML(html)  # raises RecursionError\n```\n\nTest environment: CPython 3.14.3, macOS ARM64 (Apple Silicon), justhtml 1.9.1, default recursion limit (1000)\n\n| Input | Size | Result |\n|-------|------|--------|\n| `\u003cdiv\u003e` \u00d7 500 | 5,501 bytes | OK |\n| `\u003cdiv\u003e` \u00d7 800 | 8,801 bytes | OK |\n| `\u003cdiv\u003e` \u00d7 1000 | 11,001 bytes | RecursionError |\n\nThe error occurs with both `sanitize=True` (default) and `sanitize=False`.\n\n### Impact\n\nAn attacker who can supply HTML for parsing can trigger an unhandled `RecursionError` during `JustHTML()` construction. The error is triggered during construction and is not avoided by `justhtml` configuration alone; mitigating it requires host-application exception handling or input constraints. Depending on the host application\u0027s exception handling, this can abort parsing, fail requests, or terminate a worker/process.\n\n### Suggested Fix\n\nConvert the recursive tree traversal functions to iterative implementations using an explicit stack. Example for `_find_elements`:\n\n```python\ndef _find_elements(self, node: Any, name: str, result: list[Any]) -\u003e None:\n    stack = [node]\n    while stack:\n        current = stack.pop()\n        if current.name == name:\n            result.append(current)\n        if current.has_child_nodes():\n            stack.extend(reversed(current.children))\n```\n\nThe same conversion should be applied to `_find_element`, `clone_node(deep=True)`, `_node_to_html()`, and `_to_markdown_walk()`.",
  "id": "GHSA-v7cf-c9rm-wm3j",
  "modified": "2026-08-25T16:40:34Z",
  "published": "2026-03-17T14:07:38Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/EmilStenstrom/justhtml/security/advisories/GHSA-v7cf-c9rm-wm3j"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-9769"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/EmilStenstrom/justhtml"
    },
    {
      "type": "WEB",
      "url": "https://github.com/EmilStenstrom/justhtml/releases/tag/v1.10.0"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/justhtml-before-denial-of-service-via-deeply-nested-html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Uncontrolled recursion DoS in JustHTML() via deeply nested HTML"
}

GHSA-V84H-MWMJ-46PF

Vulnerability from github – Published: 2022-05-13 01:22 – Updated: 2022-05-13 01:22
VLAI
Details

An issue was discovered in singledocparser.cpp in yaml-cpp (aka LibYaml-C++) 0.6.2. Stack Exhaustion occurs in YAML::SingleDocParser, and there is a stack consumption problem caused by recursive stack frames: HandleCompactMap, HandleMap, HandleFlowSequence, HandleSequence, HandleNode. Remote attackers could leverage this vulnerability to cause a denial-of-service via a cpp file.

Severity
6.5 (Medium)
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Show details on source website
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{
  "affected": [],
  "aliases": [
    "CVE-2019-6292"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-674"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2019-01-15T00:29:00Z",
    "severity": "MODERATE"
  },
  "details": "An issue was discovered in singledocparser.cpp in yaml-cpp (aka LibYaml-C++) 0.6.2. Stack Exhaustion occurs in YAML::SingleDocParser, and there is a stack consumption problem caused by recursive stack frames: HandleCompactMap, HandleMap, HandleFlowSequence, HandleSequence, HandleNode. Remote attackers could leverage this vulnerability to cause a denial-of-service via a cpp file.",
  "id": "GHSA-v84h-mwmj-46pf",
  "modified": "2022-05-13T01:22:41Z",
  "published": "2022-05-13T01:22:41Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2019-6292"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jbeder/yaml-cpp/issues/657"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-V9QG-3J8P-R63V

Vulnerability from github – Published: 2019-08-06 01:43 – Updated: 2024-09-20 16:09
VLAI
Summary
Uncontrolled Recursion in Django
Details

An issue was discovered in Django 1.11.x before 1.11.23, 2.1.x before 2.1.11, and 2.2.x before 2.2.4. If passed certain inputs, django.utils.encoding.uri_to_iri could lead to significant memory usage due to a recursion when repercent-encoding invalid UTF-8 octet sequences.

Severity
7.5 (High)
CVSS:3.0/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
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "Django"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.11a1"
            },
            {
              "fixed": "1.11.23"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "Django"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.1a1"
            },
            {
              "fixed": "2.1.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "Django"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.2a1"
            },
            {
              "fixed": "2.2.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2019-14235"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-674"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2019-08-06T01:34:47Z",
    "nvd_published_at": "2019-08-02T15:15:00Z",
    "severity": "HIGH"
  },
  "details": "An issue was discovered in Django 1.11.x before 1.11.23, 2.1.x before 2.1.11, and 2.2.x before 2.2.4. If passed certain inputs, django.utils.encoding.uri_to_iri could lead to significant memory usage due to a recursion when repercent-encoding invalid UTF-8 octet sequences.",
  "id": "GHSA-v9qg-3j8p-r63v",
  "modified": "2024-09-20T16:09:20Z",
  "published": "2019-08-06T01:43:31Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2019-14235"
    },
    {
      "type": "WEB",
      "url": "https://docs.djangoproject.com/en/dev/releases/security"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-v9qg-3j8p-r63v"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/django/django"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/django/PYSEC-2019-14.yaml"
    },
    {
      "type": "WEB",
      "url": "https://groups.google.com/forum/#!topic/django-announce/jIoju2-KLDs"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/STVX7X7IDWAH5SKE6MBMY3TEI6ZODBTK"
    },
    {
      "type": "WEB",
      "url": "https://seclists.org/bugtraq/2019/Aug/15"
    },
    {
      "type": "WEB",
      "url": "https://security.gentoo.org/glsa/202004-17"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20190828-0002"
    },
    {
      "type": "WEB",
      "url": "https://www.debian.org/security/2019/dsa-4498"
    },
    {
      "type": "WEB",
      "url": "https://www.djangoproject.com/weblog/2019/aug/01/security-releases"
    },
    {
      "type": "WEB",
      "url": "http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00006.html"
    },
    {
      "type": "WEB",
      "url": "http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00025.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Uncontrolled Recursion in Django"
}

GHSA-VC69-VR6F-4X67

Vulnerability from github – Published: 2026-05-15 00:30 – Updated: 2026-05-15 00:30
VLAI
Details

Stack exhaustion vulnerability in the MongoDB PHP driver can cause application crashes when processing deeply nested BSON documents in unusual circumstances when the source of these BSON documents is not MongoDB Server.

Severity
5.9 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
6.0 (Medium)
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2026-6811"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-674"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-14T22:16:45Z",
    "severity": "MODERATE"
  },
  "details": "Stack exhaustion vulnerability in the MongoDB PHP driver can cause application crashes when processing deeply nested BSON documents in unusual circumstances when the source of these BSON documents is not MongoDB Server.",
  "id": "GHSA-vc69-vr6f-4x67",
  "modified": "2026-05-15T00:30:30Z",
  "published": "2026-05-15T00:30:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-6811"
    },
    {
      "type": "WEB",
      "url": "https://jira.mongodb.org/browse/PHPC-2636"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/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-VCG7-GX5W-X44C

Vulnerability from github – Published: 2026-05-06 12:30 – Updated: 2026-05-08 15:31
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix signededness bug in smb_direct_prepare_negotiation()

smb_direct_prepare_negotiation() casts an unsigned __u32 value from sp->max_recv_size and req->preferred_send_size to a signed int before computing min_t(int, ...). A maliciously provided preferred_send_size of 0x80000000 will return as smaller than max_recv_size, and then be used to set the maximum allowed alowed receive size for the next message.

By sending a second message with a large value (>1420 bytes) the attacker can then achieve a heap buffer overflow.

This fix replaces min_t(int, ...) with min_t(u32)

Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2026-43185"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-674"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-06T12:16:37Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix signededness bug in smb_direct_prepare_negotiation()\n\nsmb_direct_prepare_negotiation() casts an unsigned __u32 value\nfrom sp-\u003emax_recv_size and req-\u003epreferred_send_size to a signed\nint before computing min_t(int, ...). A maliciously provided\npreferred_send_size of 0x80000000 will return as smaller than\nmax_recv_size, and then be used to set the maximum allowed\nalowed receive size for the next message.\n\nBy sending a second message with a large value (\u003e1420 bytes)\nthe attacker can then achieve a heap buffer overflow.\n\nThis fix replaces min_t(int, ...) with min_t(u32)",
  "id": "GHSA-vcg7-gx5w-x44c",
  "modified": "2026-05-08T15:31:16Z",
  "published": "2026-05-06T12:30:32Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43185"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/55abc475d096da4a5356b6efb0cfdc6156bc1550"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6b4f875aac344cdd52a1f34cc70ed2f874a65757"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ceae058eb707ddd0d68f0872f9d9f23b7c30c37b"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}
Mitigation
Implementation

Ensure that an end condition will be reached under all logic conditions. The end condition may include checking against the depth of recursion and exiting with an error if the recursion goes too deep. The complexity of the end condition contributes to the effectiveness of this action.

Mitigation
Implementation

Increase the stack size.

CAPEC-230: Serialized Data with Nested Payloads

Applications often need to transform data in and out of a data format (e.g., XML and YAML) by using a parser. It may be possible for an adversary to inject data that may have an adverse effect on the parser when it is being processed. Many data format languages allow the definition of macro-like structures that can be used to simplify the creation of complex structures. By nesting these structures, causing the data to be repeatedly substituted, an adversary can cause the parser to consume more resources while processing, causing excessive memory consumption and CPU utilization.

CAPEC-231: Oversized Serialized Data Payloads

An adversary injects oversized serialized data payloads into a parser during data processing to produce adverse effects upon the parser such as exhausting system resources and arbitrary code execution.

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