CVE-2025-4373: glib2.0 Buffer Underflow

Vulnerability summary

CVE-2025-4373 is a medium (CVSS 4.8) Buffer Underflow vulnerability in glib2.0. EPSS estimates a 0.64% chance of exploitation in the next 30 days, higher than 49.4% of scored vulnerabilities.

Timeline

1. 06-05-2025
   PublishedVulnerability first disclosed.
2. 15-10-2026
   Last modifiedVulnerability information updated.

Description

A flaw was found in GLib, which is vulnerable to an integer overflow in the g_string_insert_unichar() function. When the position at which to insert the character is large, the position will overflow, leading to a buffer underwrite.

• CWE-124Buffer Underwrite ('Buffer Underflow')The product writes to a buffer using an index or pointer that references a memory location prior to the beginning of the buffer.