CVE-2026-91142

A flaw was found in Cockpit. An integer overflow vulnerability in the `do_lastlog()` function, specifically in the offset calculation for `lastlog` entries on ILP32 (Integer, Long, Pointer 32-bit) builds, can be exploited. A low-privileged authenticated user with a specially provisioned large User ID (UID) can cause the computed offset to wrap around. This allows the user to perform unauthorized reads and writes to other users' `lastlog` records, potentially disclosing or altering sensitive login accounting information.

• https://access.redhat.com/security/cve/CVE-2026-91142
• https://bugzilla.redhat.com/show_bug.cgi?id=2479459