py-pdf/pypdf · Security
pypdf: Possible large memory usage for large /ToUnicode streams
- GHSA ID
- GHSA-fp3f-mc75-235c
- CVE ID
- CVE-2026-71870
- Severity
- medium
- Published
- Updated
- CVSS v4
- 4.8 · 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
Description
Impact
An attacker who uses this vulnerability can craft a PDF which leads to large memory consumption. This requires parsing the /ToUnicode entry of a font with unusually large values, for example during text extraction.
Patches
This has been fixed in pypdf==6.15.0.
Workarounds
If you cannot upgrade yet, consider applying the changes from PR #3944.
CWEs
- CWE-400 · Uncontrolled Resource Consumption
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 ↗
- https://github.com/advisories/GHSA-fp3f-mc75-235c ↗