CVE-2026-102997

UNKNOWN 0.0

pypdf: Possible long runtimes for partially malformed FlateDecode streams (Follow-up)

CVSS Score

0.0

EPSS Score

0.0%

EPSS Percentile

0th

pypdf is a free and open-source pure-python PDF library. Prior to 6.18.1, a crafted PDF containing a partially malformed /FlateDecode stream with padded data can force pypdf/filters.py to use inefficient byte-by-byte decompression while the earlier recovery counter fails to advance for bytes that successfully decode, causing long runtimes and application unavailability. This is a residual issue after the malformed FlateDecode recovery fix. This issue is fixed in version 6.18.1.

CWE	CWE-400 CWE-407
Vendor	py-pdf
Product	pypdf
Published	Sep 30, 2026

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Affected Versions

py-pdf / pypdf

< 6.18.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/py-pdf/pypdf/security/advisories/GHSA-jw7q-gvrg-4vj3 github.com: https://github.com/py-pdf/pypdf/pull/4073 github.com: https://github.com/py-pdf/pypdf/commit/d9d38cf99b115deb562d3b68f36c33027bc04f79 github.com: https://github.com/py-pdf/pypdf/releases/tag/6.18.1