CVE-2026-71870

pypdf: Possible large memory usage for large /ToUnicode streams

State: Published
Severity: 4.8 Medium
Published: Aug 7, 2026
Updated: Aug 10, 2026
Reserved: Aug 7, 2026

Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, a crafted PDF can cause large memory consumption when pypdf/_cmap.py function parse_bfrange parses unusually large source-code or destination-string tokens in a font /ToUnicode CMap during text extraction. This issue is fixed in 6.15.0.

Scores

CVSS	Score	Vector	Source
4.0	4.8 Medium	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N	GitHub_M

Weaknesses

CWE-400 Uncontrolled Resource Consumption

Affected Products

Product	Versions
pypdfpy-pdf	< 6.15.0Affected

References

https://github.com/py-pdf/pypdf/security/advisories/GHSA-fp3f-mc75-235c
https://github.com/py-pdf/pypdf/pull/3944
https://github.com/py-pdf/pypdf/commit/afba8080e19d29a3c256a742b340995e695b35aa
https://github.com/py-pdf/pypdf/releases/tag/6.15.0

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