CVE-2026-82398
pypdf: Inefficient handling of non-whitespace inputs in read_until_whitespace
Description
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.
No summary for this CVE yet.
Weaknesses
Affected Products
py-pdf
package-ecosystemaka pypdf, pypdf2
pypdfOn-prem
OSS Libraries / pypiExploitability
No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
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MITRE ATT&CK
1 technique Impact
References
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
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