Vulnerability Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.7.1, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a malformed /FlateDecode stream, where the byte-by-byte decompression is used. This vulnerability is fixed in 6.7.1.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Pypdf Project | Pypdf | < 6.7.1 |
Related Weaknesses (CWE)
References
- https://github.com/py-pdf/pypdf/commit/7905842d833f899f1d3228af7e7467ad80277016Patch
- https://github.com/py-pdf/pypdf/pull/3644Issue TrackingPatch
- https://github.com/py-pdf/pypdf/releases/tag/6.7.1ProductRelease Notes
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-9mvc-8737-8j8hPatchVendor Advisory
FAQ
What is CVE-2026-27026?
CVE-2026-27026 is a vulnerability with a CVSS score of 5.5 (MEDIUM). pypdf is a free and open-source pure-python PDF library. Prior to 6.7.1, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a malformed /FlateDecode st...
How severe is CVE-2026-27026?
CVE-2026-27026 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-27026?
Check the references section above for vendor advisories and patch information. Affected products include: Pypdf Project Pypdf.