GLib contains a buffer over‑read in the function g_io_channel_read_line_backend() when a custom line terminator longer than one byte is set. The memcmp operation then reads past the end of the GString buffer, potentially exposing up to seven bytes of adjacent memory or triggering a denial of service if the over‑read crosses a page boundary. This flaw is identified as CWE‑126, an unsafe buffer handling vulnerability, and can lead to a minor information disclosure or service interruption.

Affected systems include GNOME:GLib, Red Hat Enterprise Linux 10, 6, 7, 8, 9 and Red Hat Hardened Images, all of which ship the vulnerable GLib versions referenced in the advisory.

The CVSS score of 6.5 reflects a moderate severity impact. The EPSS score is not available, so the exact exploitation probability remains unknown, and the vulnerability is not listed in the CISA KEV catalog. Exploitation would require an application that allows an arbitrary custom line terminator to be set, such as many network services built with GLib. Because the over‑read only reveals a small piece of data and the attack surface is limited to the applications that invoke g_io_channel_read_line_backend(), the risk of widespread exploitation is moderate and likely local; however, any privileged application using a custom terminator could be impacted.