medium6.5
CVE-2026-41312
pypdf: Manipulated FlateDecode predictor parameters can exhaust RAM
Impact
pypdf is a free and open-source pure-python PDF library. An attacker who uses a vulnerability present in versions prior to 6.10.2 can craft a PDF which leads to the RAM being exhausted. This requires accessing a stream compressed using `/FlateDecode` with a `/Predictor` unequal 1 and large predictor parameters. This has been fixed in pypdf 6.10.2. As a workaround, one may apply the changes from the patch manually.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | pypdf | < 6.10.2 | 6.10.2 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Pypdf Project | Pypdf | before 6.10.2 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-7gw9-cf7v-778f
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-7gw9-cf7v-778f
- https://github.com/py-pdf/pypdf/pull/3734
- https://github.com/py-pdf/pypdf/releases/tag/6.10.2
- https://nvd.nist.gov/vuln/detail/CVE-2026-41312
- https://github.com/py-pdf/pypdf/commit/ac734dab4eef92bcce50d503949b4d9887d89f11