medium6.9
CVE-2026-28804
pypdf vulnerable to inefficient decoding of ASCIIHexDecode streams
Impact
### 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](https://github.com/py-pdf/pypdf/releases/tag/6.7.5). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3666](https://github.com/py-pdf/pypdf/pull/3666).
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | pypdf | < 6.7.5 | 6.7.5 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Pypdf Project | Pypdf | before 6.7.5 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/py-pdf/pypdf/commit/648c627d2657447dfb1773412af05a0a5103b98f
- https://github.com/py-pdf/pypdf/pull/3666
- https://github.com/py-pdf/pypdf/releases/tag/6.7.5
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-9m86-7pmv-2852
- https://github.com/advisories/GHSA-9m86-7pmv-2852
- https://nvd.nist.gov/vuln/detail/CVE-2026-28804