CVE-2026-82398

UNKNOWN 0.0

pypdf: Inefficient handling of non-whitespace inputs in read_until_whitespace

CVSS Score

0.0

EPSS Score

0.0%

EPSS Percentile

0th

pypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, an attacker can craft a PDF that causes long runtimes when the pypdf/_utils.py function read_until_whitespace reads a stream containing a long run of bytes without whitespace. The function repeatedly performs immutable bytes concatenation in a one-byte loop, causing quadratic processing cost for the long non-whitespace input. This issue is fixed in version 6.15.0.

CWE	CWE-407
Vendor	py-pdf
Product	pypdf
Published	Aug 31, 2026

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Affected Versions

py-pdf / pypdf

< 6.15.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/py-pdf/pypdf/security/advisories/GHSA-fc8x-2rww-xw9m github.com: https://github.com/py-pdf/pypdf/pull/3947 github.com: https://github.com/py-pdf/pypdf/commit/4959848e057e37c218dccad7465259210923faaa github.com: https://github.com/py-pdf/pypdf/releases/tag/6.15.0