pypdf is a free and open-source pure-python PDF library.

Code

The project this record applies to. Exploit listings stay in References.

• Repository · github.com

Timeline

Detection, updates, and resolution for this record.

1. Feb 20, 2026 · NIST NVD

   Detected

   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.

2. Jun 17, 2026 · NIST NVD

   Updated

   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.

Affected

• cpe pypdf project/pypdfversion unspecified

Sources

• NIST NVDVulnerability recordCVE-2026-27026

  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

  nvd.nist.gov

References

• Patch · github.com
• Issue Tracking · github.com
• Product · github.com
• Patch · github.com