CVE-2026-48156

Description

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.

References

• https://github.com/py-pdf/pypdf/pull/3791
• https://github.com/py-pdf/pypdf/releases/tag/6.12.0
• https://github.com/py-pdf/pypdf/security/advisories/GHSA-248m-82v9-q6g6