PYSEC-2026-1830

Vulnerability from pysec - Published: 2026-07-07 16:03 - Updated: 2026-07-07 17:25
VLAI
Details

Impact

An attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires just reading the file if a series of FlateDecode filters is used on a malicious cross-reference stream. Other content streams are affected on explicit access.

Patches

This has been fixed in pypdf==6.0.0.

Workarounds

If you cannot upgrade yet, you might want to implement the workaround for pypdf.filters.decompress yourself: https://github.com/py-pdf/pypdf/blob/0dd57738bbdcdb63f0fb43d8a6b3d222b6946595/pypdf/filters.py#L72-L143

References

This issue has been reported in #3429 and fixed in #3430.

Severity
6.6 (Medium)
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:U
Impacted products
Name purl
pypdf pkg:pypi/pypdf
Aliases
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "pypdf",
        "purl": "pkg:pypi/pypdf"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.0.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0",
        "1.1",
        "1.10",
        "1.11",
        "1.12",
        "1.13",
        "1.2",
        "1.3",
        "1.4",
        "1.5",
        "1.6",
        "1.7",
        "1.8",
        "1.9",
        "3.1.0",
        "3.10.0",
        "3.11.0",
        "3.11.1",
        "3.12.0",
        "3.12.1",
        "3.12.2",
        "3.13.0",
        "3.14.0",
        "3.15.0",
        "3.15.1",
        "3.15.2",
        "3.15.3",
        "3.15.4",
        "3.15.5",
        "3.16.0",
        "3.16.1",
        "3.16.2",
        "3.16.3",
        "3.16.4",
        "3.17.0",
        "3.17.1",
        "3.17.2",
        "3.17.3",
        "3.17.4",
        "3.2.0",
        "3.2.1",
        "3.3.0",
        "3.4.0",
        "3.4.1",
        "3.5.0",
        "3.5.1",
        "3.5.2",
        "3.6.0",
        "3.7.0",
        "3.7.1",
        "3.8.0",
        "3.8.1",
        "3.9.0",
        "3.9.1",
        "4.0.0",
        "4.0.1",
        "4.0.2",
        "4.1.0",
        "4.2.0",
        "4.3.0",
        "4.3.1",
        "5.0.0",
        "5.0.1",
        "5.1.0",
        "5.2.0",
        "5.3.0",
        "5.3.1",
        "5.4.0",
        "5.5.0",
        "5.6.0",
        "5.6.1",
        "5.7.0",
        "5.8.0",
        "5.9.0"
      ]
    }
  ],
  "aliases": [
    "CVE-2025-55197",
    "GHSA-7hfw-26vp-jp8m"
  ],
  "details": "### Impact\nAn attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires just reading the file if a series of FlateDecode filters is used on a malicious cross-reference stream. Other content streams are affected on explicit access.\n\n### Patches\nThis has been fixed in [pypdf==6.0.0](https://github.com/py-pdf/pypdf/releases/tag/6.0.0).\n\n### Workarounds\nIf you cannot upgrade yet, you might want to implement the workaround for `pypdf.filters.decompress` yourself: https://github.com/py-pdf/pypdf/blob/0dd57738bbdcdb63f0fb43d8a6b3d222b6946595/pypdf/filters.py#L72-L143\n\n### References\nThis issue has been reported in #3429 and fixed in #3430.",
  "id": "PYSEC-2026-1830",
  "modified": "2026-07-07T17:25:12.908281Z",
  "published": "2026-07-07T16:03:01.099738Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/security/advisories/GHSA-7hfw-26vp-jp8m"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-55197"
    },
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/issues/3429"
    },
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/pull/3430"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/py-pdf/pypdf"
    },
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/blob/0dd57738bbdcdb63f0fb43d8a6b3d222b6946595/pypdf/filters.py#L72-L143"
    },
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/releases/tag/6.0.0"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/pypdf"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-7hfw-26vp-jp8m"
    }
  ],
  "severity": [
    {
      "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:U",
      "type": "CVSS_V4"
    }
  ],
  "summary": "PyPDF\u0027s Manipulated FlateDecode streams can exhaust RAM"
}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.