py-pdf/pypdf · Security
pypdf vulnerable to inefficient decoding of ASCIIHexDecode streams
- GHSA ID
- GHSA-9m86-7pmv-2852
- CVE ID
- CVE-2026-28804
- Severity
- medium
- Published
- Updated
- CVSS v4
- 6.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/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 long runtimes. This requires accessing a stream which uses the /ASCIIHexDecode filter.
Patches
This has been fixed in pypdf==6.7.5.
Workarounds
If you cannot upgrade yet, consider applying the changes from PR #3666.
CWEs
- CWE-407 · Inefficient Algorithmic Complexity
References
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-9m86-7pmv-2852 ↗
- https://github.com/py-pdf/pypdf/pull/3666 ↗
- https://github.com/py-pdf/pypdf/releases/tag/6.7.5 ↗
- https://nvd.nist.gov/vuln/detail/CVE-2026-28804 ↗
- https://github.com/py-pdf/pypdf/commit/648c627d2657447dfb1773412af05a0a5103b98f ↗
- https://github.com/advisories/GHSA-9m86-7pmv-2852 ↗