pypdf: Manipulated RunLengthDecode streams can exhaust RAM

GHSA-f2v5-7jq9-h8cg · CVE-2026-28351 · PYSEC-2026-3017

Published Feb 28, 2026 · Modified Sep 10, 2026

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Description

Impact

An attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing the content stream using the RunLengthDecode filter.

Patches

This has been fixed in pypdf==6.7.4.

Workarounds

If you cannot upgrade yet, consider applying the changes from PR #3664.

References

WEB https://github.com/py-pdf/pypdf/security/advisories/GHSA-f2v5-7jq9-h8cg
ADVISORY https://nvd.nist.gov/vuln/detail/CVE-2026-28351
WEB https://github.com/py-pdf/pypdf/pull/3664
WEB https://github.com/py-pdf/pypdf/commit/f309c6003746414dc7b5048c19e6d879ff2dc858
PACKAGE https://github.com/py-pdf/pypdf
WEB https://github.com/py-pdf/pypdf/releases/tag/6.7.4

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