CVE-2026-1484 Glib: integer overflow leading to buffer underflow and out-of-bounds write in glib g_base64_encode()

Description

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.

Exploitable remotely over the network, without an account and if a user takes an action; the impact on data or service is limited.

Attack vector

Network

Attack complexity

High

Privileges required

None

Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

Low

Affected products and versions