medium6.0
CVE-2026-113791
pypdf: Possible large memory usage when parsing content streams
Impact
pypdf is a free and open-source pure-python PDF library. Prior to 6.21.0, an attacker can craft a PDF containing a content stream with many small operations, causing parsing to consume large amounts of memory. This issue is fixed in version 6.21.0.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | pypdf | < 6.21.0 | 6.21.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-cgf9-327m-v77c
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-cgf9-327m-v77c
- https://nvd.nist.gov/vuln/detail/CVE-2026-113791
- https://github.com/py-pdf/pypdf/pull/4218
- https://github.com/py-pdf/pypdf/commit/18bd2981a74479483a0b9507602c58a63d6c9b12
- https://github.com/py-pdf/pypdf/releases/tag/6.21.0