CVE-2026-71267
microtar's mtar_write_file_header() and mtar_write_dir_header() functions (src/microtar.c) copy a caller-supplied entry name into the 100-byte `name` field of a stack-allocated mtar_header_t via strcpy(h.name, name), with no check that strlen(name) is less than 100 before the copy. Any application that calls these functions with an externally-influenced filename longer than 99 characters (e.g. when archiving user-supplied or attacker-controlled filenames) triggers a stack buffer overflow.
No public exploitation has been reported so far. No distribution fix is listed yet; apply vendor mitigations and monitor.
Recommended action: Track your distribution's security tracker and apply the fix as soon as it ships.
Severity metrics
CVSS 3.1 : 9.8 CRITICAL
Vector: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected & fixed versions by distribution
Versions are the native distribution strings (backport-aware): RHEL/Debian/SUSE backport fixes, so compare with the distro version comparator (dpkg / rpm / vercmp), not the upstream version.
No affected package in the tracked watchlist yet (Debian, Ubuntu, Arch, SUSE, Red Hat...). Triage may still be pending.