CVE-2026-58012: Gnome Glib

High severity, CVSS 8.2. EPSS: 0.5% chance of exploitation in the next 30 days.

A flaw was found in GLib. A buffer over-read can occur in the g_regex_replace function when used with the `G_REGEX_RAW` compile flag and case-change replacement escapes because the string_append function processes matched substrings using UTF-8 functions that assume valid UTF-8 input, even when the string is treated as raw bytes. This vulnerability can cause a minor information disclosure of 1-5 bytes and a denial of service when the buffer over-read crosses a page boundary.

Affected products

• Gnome Glib: before 2.86.5 (fixed in 2.86.5); version 2.88.0 only
• Red Hat Enterprise Linux: version 6.0 only; version 7.0 only; version 8.0 only; version 9.0 only; version 10.0 only

Published 2026-06-30. Last modified 2026-10-06.