Vulnerability in bzip2 software

CERT Polska has received a report about vulnerability in bzip2 software and participated in coordination of its disclosure.

The vulnerabilityCVE-2026-42250: bzip2 contains an off‑by‑one error in the bzip2recover utility. When processing a specially crafted file, the application performs an out‑of‑bounds write to a global buffer, resulting in memory corruption and a crash (denial of service).

This issue was fixed in bzip2 patch 35d122a3df8b0cc4082a4d89fdc6ee99f375fe67

We thank Michał Majchrowicz and Marcin Wyczechowski from AFINE Team for the responsible vulnerability report.