CVE-2026-22690

MEDIUM5.3

pypdf has possible long runtimes for missing /Root object with large /Size values

Published Jan 10, 2026

Modified 9 months ago

Details

pypdf is a free and open-source pure-python PDF library. Prior to version 6.6.0, pypdf has possible long runtimes for missing /Root object with large /Size values. An attacker who uses this vulnerability can craft a PDF which leads to possibly long runtimes for actually invalid files. This can be achieved by omitting the /Root entry in the trailer, while using a rather large /Size value. Only the non-strict reading mode is affected. This issue has been patched in version 6.6.0.

References

WEB

https://github.com/py-pdf/pypdf/commit/294165726b646bb7799be1cc787f593f2fdbcf45

WEB

https://github.com/py-pdf/pypdf/pull/3594

WEB

https://github.com/py-pdf/pypdf/releases/tag/6.6.0

WEB

https://github.com/py-pdf/pypdf/security/advisories/GHSA-4xc4-762w-m6cg

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2026-22690

CVSS Analysis