py-pdf/pypdf · Security
pypdf has possible long runtimes/large memory usage for large /ToUnicode streams
- GHSA ID
- GHSA-wgvp-vg3v-2xq3
- CVE ID
- CVE-2026-27025
- Severity
- medium
- Published
- Updated
- CVSS v4
- 6.9 · CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Description
Impact
An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and 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==6.7.1.
Workarounds
If you cannot upgrade yet, consider applying the changes from PR #3646.
CWEs
- CWE-834 · Excessive Iteration
References
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-wgvp-vg3v-2xq3 ↗
- https://github.com/py-pdf/pypdf/pull/3646 ↗
- https://github.com/py-pdf/pypdf/commit/77d7b8d7cfbe8dd179858dfa42666f73fc6e57a2 ↗
- https://github.com/py-pdf/pypdf/releases/tag/6.7.1 ↗
- https://nvd.nist.gov/vuln/detail/CVE-2026-27025 ↗
- https://github.com/advisories/GHSA-wgvp-vg3v-2xq3 ↗