pypdf: Inefficient decoding of FlateDecode PNG predictor streams

GHSA-5hgr-hg42-57jg · CVE-2026-49460 · PYSEC-2026-3010

Published Jun 16, 2026 · Modified Jul 13, 2026

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Description

Impact

An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the /FlateDecode filter with a PNG predictor.

Patches

This has been fixed in pypdf==6.12.2.

Workarounds

If you cannot upgrade yet, consider applying the changes from PR #3806.

References

WEB https://github.com/py-pdf/pypdf/security/advisories/GHSA-5hgr-hg42-57jg
WEB https://github.com/py-pdf/pypdf/pull/3806
PACKAGE https://github.com/py-pdf/pypdf
WEB https://github.com/py-pdf/pypdf/releases/tag/6.12.2

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