MEDIUM 6.9 NVD
CVE-2026-82398
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 functio
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.
References
- https://github.com/py-pdf/pypdf/commit/4959848e057e37c218dccad7465259210923faaa
- https://github.com/py-pdf/pypdf/pull/3947
- https://github.com/py-pdf/pypdf/releases/tag/6.15.0
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-fc8x-2rww-xw9m
This medium severity vulnerability with a CVSS score of 6.9 was published on 2026-08-31 via NVD.
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