CVE-2025-71263: Opengroup Unix

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

In UNIX Fourth Research Edition (v4), the su command is vulnerable to a buffer overflow due to the 'password' variable having a fixed size of 100 bytes. A local user can exploit this to gain root privileges. It is unlikely that UNIX v4 is running anywhere outside of a very small number of lab environments. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.

Affected products

• Opengroup Unix: version 4 only

Published 2026-03-13. Last modified 2026-06-17.