CVE-2026-16118

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.

To exploit this issue, an attacker must convince a user to install a malicious MIME magic file in a user-writable XDG data location (e.g., in the $XDG_DATA_HOME/mime/magic path) and process it with an application performing MIME type detection, limiting its exposure. Also, only little-endian systems are vulnerable. Due to these reasons, this issue has been rated with a moderate severity.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Do not install a MIME magic file or content from untrusted sources.