CVE-2026-16118 Xdgmime: heap-based buffer overflow in _xdg_mime_magic_parse_magic_line() in xdgmimemagic.c

High 7.1 Published 17 Jul 2026 Updated 29 Oct 2026

Heap-based buffer overflow in xdgmime allows attackers to cause crashes or execute code via malicious MIME magic files.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: A user has to click or open something
Fix: Available

What is CVE-2026-16118?

CVE-2026-16118 is a high-severity memory corruption vulnerability in Cert Manager support for Red Hat OpenShift release 1.17, published on 17 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

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.

Weakness: CWE-122

Which versions are affected by CVE-2026-16118?

Linux distribution packages (40)

`glib2` AlmaLinux:10	All versions	`2.80.4-12.el10_2.22`
`glib2-devel` AlmaLinux:10	All versions	`2.80.4-12.el10_2.22`
`glib2-doc` AlmaLinux:10	All versions	`2.80.4-12.el10_2.22`
`glib2-static` AlmaLinux:10	All versions	`2.80.4-12.el10_2.22`
`glib2-tests` AlmaLinux:10	All versions	`2.80.4-12.el10_2.22`
`glib2` AlmaLinux:8	All versions	`2.56.4-178.el8_10`
`glib2-devel` AlmaLinux:8	All versions	`2.56.4-178.el8_10`
`glib2-doc` AlmaLinux:8	All versions	`2.56.4-178.el8_10`
`glib2-fam` AlmaLinux:8	All versions	`2.56.4-178.el8_10`
`glib2-static` AlmaLinux:8	All versions	`2.56.4-178.el8_10`
`glib2-tests` AlmaLinux:8	All versions	`2.56.4-178.el8_10`
`glib2` AlmaLinux:9	All versions	`2.68.4-19.el9_8.10`
`glib2-devel` AlmaLinux:9	All versions	`2.68.4-19.el9_8.10`
`glib2-doc` AlmaLinux:9	All versions	`2.68.4-19.el9_8.10`
`glib2-static` AlmaLinux:9	All versions	`2.68.4-19.el9_8.10`
`glib2-tests` AlmaLinux:9	All versions	`2.68.4-19.el9_8.10`
`glib2` Red Hat:enterprise_linux:10.2	All versions	`0:2.80.4-12.el10_2.22`
`glib2-debuginfo` Red Hat:enterprise_linux:10.2	All versions	`0:2.80.4-12.el10_2.22`
`glib2-debugsource` Red Hat:enterprise_linux:10.2	All versions	`0:2.80.4-12.el10_2.22`
`glib2-devel` Red Hat:enterprise_linux:10.2	All versions	`0:2.80.4-12.el10_2.22`
`glib2-devel-debuginfo` Red Hat:enterprise_linux:10.2	All versions	`0:2.80.4-12.el10_2.22`
`glib2-doc` Red Hat:enterprise_linux:10.2	All versions	`0:2.80.4-12.el10_2.22`
`glib2-static` Red Hat:enterprise_linux:10.2	All versions	`0:2.80.4-12.el10_2.22`
`glib2-tests` Red Hat:enterprise_linux:10.2	All versions	`0:2.80.4-12.el10_2.22`
`glib2-tests-debuginfo` Red Hat:enterprise_linux:10.2	All versions	`0:2.80.4-12.el10_2.22`
`glib2` Red Hat:enterprise_linux:8::baseos	All versions	`0:2.56.4-178.el8_10`
`glib2-debuginfo` Red Hat:enterprise_linux:8::baseos	All versions	`0:2.56.4-178.el8_10`
`glib2-debugsource` Red Hat:enterprise_linux:8::baseos	All versions	`0:2.56.4-178.el8_10`
`glib2-devel` Red Hat:enterprise_linux:8::baseos	All versions	`0:2.56.4-178.el8_10`
`glib2-devel-debuginfo` Red Hat:enterprise_linux:8::baseos	All versions	`0:2.56.4-178.el8_10`
`glib2-fam` Red Hat:enterprise_linux:8::baseos	All versions	`0:2.56.4-178.el8_10`
`glib2-fam-debuginfo` Red Hat:enterprise_linux:8::baseos	All versions	`0:2.56.4-178.el8_10`
`glib2-tests` Red Hat:enterprise_linux:8::baseos	All versions	`0:2.56.4-178.el8_10`
`glib2-tests-debuginfo` Red Hat:enterprise_linux:8::baseos	All versions	`0:2.56.4-178.el8_10`
`glib2-debuginfo` Red Hat:enterprise_linux:8::crb	All versions	`0:2.56.4-178.el8_10`
`glib2-debugsource` Red Hat:enterprise_linux:8::crb	All versions	`0:2.56.4-178.el8_10`
`glib2-devel-debuginfo` Red Hat:enterprise_linux:8::crb	All versions	`0:2.56.4-178.el8_10`
`glib2-doc` Red Hat:enterprise_linux:8::crb	All versions	`0:2.56.4-178.el8_10`
`glib2-fam-debuginfo` Red Hat:enterprise_linux:8::crb	All versions	`0:2.56.4-178.el8_10`
`glib2-static` Red Hat:enterprise_linux:8::crb	All versions	`0:2.56.4-178.el8_10`

How do I fix CVE-2026-16118?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-16118 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-16118 exists.

Sources

Also known as ALSA-2026:64799, ALSA-2026:64800, ALSA-2026:66451, CLSA-2026-1789032075, CLSA-2026-1789206553, CLSA-2026-1789392191 and 25 more.