# CVE-2026-119204: pypdf: Possible large memory usage when parsing page tree

Status: published. Published: 2026-10-29. Updated: 2026-11-04.

pypdf is a free and open-source pure-python PDF library. Prior to 6.21.4, pypdf can consume excessive memory while parsing a crafted PDF page tree containing many shared resources. Page-tree flattening copies page dictionary and inherited resource entries without a document-wide entry budget, allowing the crafted resource structure to cause disproportionate allocations. This issue is fixed in version 6.21.4.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: security-advisories@github.com) — https://github.com/py-pdf/pypdf/commit/ea4ac663133f1b3de1d7a8f2e6fa239802fde79e
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: security-advisories@github.com) — https://github.com/py-pdf/pypdf/pull/4290
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: security-advisories@github.com) — https://github.com/py-pdf/pypdf/security/advisories/GHSA-cggf-277g-3q54
- fix: pypi (pip): GitHub reports patched versions >= 6.21.4. Check the advisory for the affected release branch. (source: GitHub GHSA-cggf-277g-3q54) — https://github.com/py-pdf/pypdf/security/advisories/GHSA-cggf-277g-3q54
- fix: pypdf (PyPI): OSV reports a fixed version 6.21.4. Check the advisory for supported release branches. (source: OSV GHSA-cggf-277g-3q54) — https://github.com/advisories/GHSA-cggf-277g-3q54

## Affected products and versions

- py-pdf / pypdf: < 6.21.4 (affected). Source: CNA: GitHub_M
-  / pypi (pypi): < 6.21.4 (affected, GitHub advisory range). Source: GitHub GHSA-cggf-277g-3q54
-  / pypdf (pypdf): 1.0 (affected, PyPI); 1.1 (affected, PyPI); 1.10 (affected, PyPI); 1.11 (affected, PyPI); 1.12 (affected, PyPI); 1.13 (affected, PyPI); 1.2 (affected, PyPI); 1.3 (affected, PyPI); 1.4 (affected, PyPI); 1.5 (affected, PyPI); 1.6 (affected, PyPI); 1.7 (affected, PyPI); 1.8 (affected, PyPI); 1.9 (affected, PyPI); 3.1.0 (affected, PyPI); 3.10.0 (affected, PyPI); 3.11.0 (affected, PyPI); 3.11.1 (affected, PyPI); 3.12.0 (affected, PyPI); 3.12.1 (affected, PyPI); 3.12.2 (affected, PyPI); 3.13.0 (affected, PyPI); 3.14.0 (affected, PyPI); 3.15.0 (affected, PyPI); 3.15.1 (affected, PyPI); 3.15.2 (affected, PyPI); 3.15.3 (affected, PyPI); 3.15.4 (affected, PyPI); 3.15.5 (affected, PyPI); 3.16.0 (affected, PyPI); 3.16.1 (affected, PyPI); 3.16.2 (affected, PyPI); 3.16.3 (affected, PyPI); 3.16.4 (affected, PyPI); 3.17.0 (affected, PyPI); 3.17.1 (affected, PyPI); 3.17.2 (affected, PyPI); 3.17.3 (affected, PyPI); 3.17.4 (affected, PyPI); 3.2.0 (affected, PyPI); 3.2.1 (affected, PyPI); 3.3.0 (affected, PyPI); 3.4.0 (affected, PyPI); 3.4.1 (affected, PyPI); 3.5.0 (affected, PyPI); 3.5.1 (affected, PyPI); 3.5.2 (affected, PyPI); 3.6.0 (affected, PyPI); 3.7.0 (affected, PyPI); 3.7.1 (affected, PyPI); 3.8.0 (affected, PyPI); 3.8.1 (affected, PyPI); 3.9.0 (affected, PyPI); 3.9.1 (affected, PyPI); 4.0.0 (affected, PyPI); 4.0.1 (affected, PyPI); 4.0.2 (affected, PyPI); 4.1.0 (affected, PyPI); 4.2.0 (affected, PyPI); 4.3.0 (affected, PyPI); 4.3.1 (affected, PyPI); 5.0.0 (affected, PyPI); 5.0.1 (affected, PyPI); 5.1.0 (affected, PyPI); 5.2.0 (affected, PyPI); 5.3.0 (affected, PyPI); 5.3.1 (affected, PyPI); 5.4.0 (affected, PyPI); 5.5.0 (affected, PyPI); 5.6.0 (affected, PyPI); 5.6.1 (affected, PyPI); 5.7.0 (affected, PyPI); 5.8.0 (affected, PyPI); 5.9.0 (affected, PyPI); 6.0.0 (affected, PyPI); 6.1.0 (affected, PyPI); 6.1.1 (affected, PyPI); 6.1.2 (affected, PyPI); 6.1.3 (affected, PyPI); 6.10.0 (affected, PyPI); 6.10.1 (affected, PyPI); 6.10.2 (affected, PyPI); 6.11.0 (affected, PyPI); 6.12.0 (affected, PyPI); 6.12.1 (affected, PyPI); 6.12.2 (affected, PyPI); 6.13.0 (affected, PyPI); 6.13.1 (affected, PyPI); 6.13.2 (affected, PyPI); 6.13.3 (affected, PyPI); 6.14.0 (affected, PyPI); 6.14.1 (affected, PyPI); 6.14.2 (affected, PyPI); 6.15.0 (affected, PyPI); 6.16.0 (affected, PyPI); 6.16.1 (affected, PyPI); 6.16.2 (affected, PyPI); 6.17.0 (affected, PyPI); 6.18.0 (affected, PyPI); 6.18.1 (affected, PyPI); 6.19.0 (affected, PyPI); 6.2.0 (affected, PyPI); 6.20.0 (affected, PyPI); 6.20.1 (affected, PyPI); 6.21.0 (affected, PyPI); 6.21.1 (affected, PyPI); 6.21.2 (affected, PyPI); 6.21.3 (affected, PyPI); 6.3.0 (affected, PyPI); 6.4.0 (affected, PyPI); 6.4.1 (affected, PyPI); 6.4.2 (affected, PyPI); 6.5.0 (affected, PyPI); 6.6.0 (affected, PyPI); 6.6.1 (affected, PyPI); 6.6.2 (affected, PyPI); 6.7.0 (affected, PyPI); 6.7.1 (affected, PyPI); 6.7.2 (affected, PyPI); 6.7.3 (affected, PyPI); 6.7.4 (affected, PyPI); 6.7.5 (affected, PyPI); 6.8.0 (affected, PyPI); 6.9.0 (affected, PyPI); 6.9.1 (affected, PyPI); 6.9.2 (affected, PyPI); Ecosystem version events: introduced 0; fixed 6.21.4. Source: OSV GHSA-cggf-277g-3q54

## NVD configuration conditions

Affected CPE matches depend on the following AND/OR and negation conditions:

```json
[
  {
    "negate": false,
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:py-pdf:pypdf:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.21.4",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ],
    "operator": "OR"
  }
]
```

## Severity and prioritization

- CVSS 4.0: 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; source: CNA: GitHub_M

- CVSS 4.0: 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/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; source: NVD: security-advisories@github.com

- CVSS 3.1: 5.5 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H; source: NVD: nvd@nist.gov

- CISA KEV: No listing in collected sources

- EPSS: 0.22% as of 2026-11-03; percentile 12.70%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-400

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/py-pdf/pypdf/security/advisories/GHSA-cggf-277g-3q54 (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/py-pdf/pypdf/pull/4290 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/py-pdf/pypdf/commit/ea4ac663133f1b3de1d7a8f2e6fa239802fde79e (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/py-pdf/pypdf/releases/tag/6.21.4 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/py-pdf/pypdf/commit/ea4ac663133f1b3de1d7a8f2e6fa239802fde79e (security-advisories@github.com; Patch)

- https://github.com/py-pdf/pypdf/pull/4290 (security-advisories@github.com; Patch)

- https://github.com/py-pdf/pypdf/releases/tag/6.21.4 (security-advisories@github.com; Release Notes)

- https://github.com/py-pdf/pypdf/security/advisories/GHSA-cggf-277g-3q54 (security-advisories@github.com; Patch, Vendor Advisory)

- https://github.com/py-pdf/pypdf/security/advisories/GHSA-cggf-277g-3q54 (GitHub Security Advisories; advisory)

- https://github.com/advisories/GHSA-cggf-277g-3q54 (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-cggf-277g-3q54 (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-119204; retrieved 2026-11-04; source updated 2026-11-04

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-119204; retrieved 2026-11-02; source updated 2026-11-02

- GitHub Security Advisories: https://github.com/py-pdf/pypdf/security/advisories/GHSA-cggf-277g-3q54; retrieved 2026-11-04; source updated 2026-10-29

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-cggf-277g-3q54; retrieved 2026-11-02; source updated 2026-10-30

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-119204; retrieved 2026-11-04; source updated Not reported

Revision: 1835652b341d92349c01af327eb19afd2b74d8cb155539aaf0b321cbbb8473d2

Canonical: https://y2.dev/cve/CVE-2026-119204

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