OESA-2026-1400

GLib is a bundle of three (formerly five) low-level system libraries written in C and developed mainly by GNOME. GLib's code was separated from GTK, so it can be used by software other than GNOME and has been developed in parallel ever since.

Security Fix(es):

A flaw was found in the GLib Base64 encoding routine when processing very large input data. Due to incorrect use of integer types during length calculation, the library may miscalculate buffer boundaries. This can cause memory writes outside the allocated buffer. Applications that process untrusted or extremely large Base64 input using GLib may crash or behave unpredictably.(CVE-2026-1484)

A flaw was found in Glib's content type parsing logic. This buffer underflow vulnerability occurs because the length of a header line is stored in a signed integer, which can lead to integer wraparound for very large inputs. This results in pointer underflow and out-of-bounds memory access. Exploitation requires a local user to install or process a specially crafted treemagic file, which can lead to local denial of service or application instability.(CVE-2026-1485)

A flaw was found in GLib. An integer overflow vulnerability in its Unicode case conversion implementation can lead to memory corruption. By processing specially crafted and extremely large Unicode strings, an attacker could trigger an undersized memory allocation, resulting in out-of-bounds writes. This could cause applications utilizing GLib for string conversion to crash or become unstable. This vulnerability has an impact on confidentiality, integrity, and availability.(CVE-2026-1489)