CVE-2026-27026

UNKNOWN 0.0

pypdf possibly has long runtimes for malformed FlateDecode streams

CVSS Score

0.0

EPSS Score

0.0%

EPSS Percentile

0th

pypdf is a free and open-source pure-python PDF library. Prior to 6.7.1, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a malformed /FlateDecode stream, where the byte-by-byte decompression is used. This vulnerability is fixed in 6.7.1.

CWE	CWE-770
Vendor	py-pdf
Product	pypdf
Published	Feb 20, 2026
Last Updated	Feb 24, 2026

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Affected Versions

py-pdf / pypdf

< 6.7.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/py-pdf/pypdf/security/advisories/GHSA-9mvc-8737-8j8h github.com: https://github.com/py-pdf/pypdf/pull/3644 github.com: https://github.com/py-pdf/pypdf/commit/7905842d833f899f1d3228af7e7467ad80277016 github.com: https://github.com/py-pdf/pypdf/releases/tag/6.7.1