medium3.3
CVE-2026-48156
pypdf: Possible long runtimes for zero-only width values in cross-reference streamsuntimes for zero-only width values in cross-reference streams
Impact
pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with /W [0 0 0] values and large /Size values. This vulnerability is fixed in 6.12.0.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | pypdf | < 6.12.0 | 6.12.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Pypdf Project | Pypdf | before 6.12.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-248m-82v9-q6g6
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-248m-82v9-q6g6
- https://nvd.nist.gov/vuln/detail/CVE-2026-48156
- https://github.com/py-pdf/pypdf/pull/3791
- https://github.com/py-pdf/pypdf/commit/507d7c9aa6ea83389b954b9c3c0c528fe5d5da70
- https://github.com/py-pdf/pypdf/releases/tag/6.12.0