GitHub Advisoryadvisory · PyPI
GHSA-9m86-7pmv-2852 pypdf vulnerable to inefficient decoding of ASCIIHexDecode streams
MEDIUM
Official page ↗
- Aliases
- CVE-2026-28804
- Ecosystem
- PyPI
- Packages
- pypdf
- Severity
- Moderate
- CVSS vector
- 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
- Weaknesses
- CWE-407
- Reviewed
- 2026-03-02
Affected packages
• PyPI pypdf: < 6.7.5 → fixed in 6.7.5
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.
Related
Alias · CVE (1)
- CVE-2026-28804 pypdf is a free and open-source pure-python PDF library. vulnerability
Weakness · CWE (1)
- CWE-407 Inefficient Algorithmic Complexity weakness
References
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-9m86-7pmv-2852 web
- https://nvd.nist.gov/vuln/detail/CVE-2026-28804 advisory
- https://github.com/py-pdf/pypdf/pull/3666 web
- https://github.com/py-pdf/pypdf/commit/648c627d2657447dfb1773412af05a0a5103b98f web
- https://github.com/py-pdf/pypdf package
- https://github.com/py-pdf/pypdf/releases/tag/6.7.5 web