High [CVE-2026-16118] heap-based buffer overflow in _xdg_mime_magic_parse_magic_line in xdgmimemagic.c

A flaw was found in xdgmime.

A heap-based buffer overflow can be triggered in _xdg_mime_magic_parse_magic_line() in the xdgmimemagic.c file on little-endian systems when an attacker-controlled MIME magic file in a user-writable XDG data location (e.g., in the $XDG_DATA_HOME/mime/magic path) is parsed by an application performing MIME type detection (e.g., via g_content_type_guess()).

When performing byte-swap, incorrect pointer arithmetic on the write side causes an out-of-bounds write of 2 bytes, resulting in an application crash or memory corruption. Also, only little-endian systems are vulnerable.

Due to these reasons, this issue has been rated with a moderate severity. Red Hat severity: Moderate — CVSS 7.1 (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H).

Weakness: CWE-122.

Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 10.0 Extended Update Support; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9; Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions; Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions; Red Hat Enterprise Linux 9.6 Extended Update Support; Red Hat Update Infrastructure 5; Red Hat Enterprise Linux 7.

Will not fix / out of support: Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9.