CVE-2025-14512: Gnome Glib Buffer Overflow Vulnerability

CVE-2025-14512 Overview

CVE-2025-14512 is a heap buffer overflow vulnerability in GLib, the low-level core library used by GNOME and many Linux applications. The flaw resides in the escape_byte_string() function within GLib's GIO (GLib Input/Output) subsystem. An integer overflow occurs when the function processes malicious file or remote filesystem attribute values, leading to a heap buffer overflow and denial-of-service (DoS) condition. The weakness is classified under CWE-190: Integer Overflow or Wraparound. Exploitation requires user interaction, typically by opening a crafted file or interacting with a malicious remote filesystem through GIO-enabled applications such as GNOME Files (Nautilus) or other consumers of GLib.

Critical Impact
A remote attacker can trigger a heap buffer overflow that crashes GLib-based applications, resulting in denial of service across GNOME desktops and any software linking against affected GLib versions.

Affected Products

GNOME GLib (all versions prior to the patched release)
Red Hat Enterprise Linux 7, 8, 9, and 10
Red Hat OpenShift 4.0

Discovery Timeline

2025-12-11 - CVE-2025-14512 published to NVD
2026-07-13 - Last updated in NVD database

Technical Details for CVE-2025-14512

Vulnerability Analysis

The vulnerability exists in the escape_byte_string() helper function of GLib's GIO module. GIO provides a modern, GObject-based API for file, network, and remote filesystem access. When GIO retrieves filesystem attributes, such as extended attributes or metadata from local files and mounted remote shares, it may invoke escape_byte_string() to render byte values in a printable form.

The function performs size calculations on attribute values before allocating a destination buffer. An attacker-controlled attribute value with a large length can cause the internal size arithmetic to wrap around, producing an undersized allocation. Subsequent writes then exceed the allocated heap region, corrupting adjacent memory and crashing the process.

Because GLib underpins GNOME and many Linux applications, any process that consumes untrusted file attributes through GIO is exposed. Attack impact is limited to availability, per the CVSS vector, but the ubiquity of GLib makes the DoS surface broad.

Root Cause

The root cause is unchecked arithmetic on attribute length values inside escape_byte_string(). Length inputs multiplied or added during buffer sizing exceed the range of the integer type used, wrapping to a small value. The resulting malloc() (or g_malloc()) returns a buffer far smaller than the data eventually written, producing a classic integer-overflow-to-buffer-overflow chain [CWE-190].

Attack Vector

Exploitation is network-adjacent with user interaction. An attacker delivers a malicious file, archive, or remote share (for example, SMB, WebDAV, or FTP mounted through GVfs) containing crafted filesystem attribute values. When a victim opens the file or navigates the share using a GIO-based application, escape_byte_string() processes the malicious attribute and the overflow triggers. No authentication or elevated privileges are required on the target system. See the GNOME GitLab Issue #3845 and Red Hat Bugzilla Report #2421339 for upstream technical detail.

Detection Methods for CVE-2025-14512

Indicators of Compromise

Unexpected crashes or SIGABRT/SIGSEGV signals in processes linked against libglib-2.0 or libgio-2.0, particularly file managers, thumbnailers, and GVfs daemons.
Core dumps referencing escape_byte_string in the crashing stack frame.
Repeated restarts of gvfsd, gvfsd-fuse, nautilus, or tracker-miner-fs when accessing specific remote shares or files.

Detection Strategies

Inventory installed GLib packages across Linux hosts and compare against the fixed versions listed in the Red Hat security advisories.
Monitor systemd-coredump and abrt logs for crashes in GLib consumers, correlating with recent file or share access events.
Deploy YARA or file-scanning rules that flag filesystem attributes with abnormally large declared lengths in archives and remote share metadata.

Monitoring Recommendations

Enable audit logging (auditd) around GVfs mount points and user file manager sessions to capture the origin of files that cause crashes.
Aggregate crash telemetry from Linux endpoints into a centralized log platform and alert on repeated failures in GLib-linked binaries.
Track vulnerable package versions using an authenticated vulnerability scanner and prioritize hosts running GNOME desktop or OpenShift nodes.

How to Mitigate CVE-2025-14512

Immediate Actions Required

Apply the GLib updates shipped in the applicable Red Hat Security Advisories, including RHSA-2026:15953, RHSA-2026:15969, RHSA-2026:19148, and RHSA-2026:7461.
Restart GLib-dependent services and user sessions after patching so that updated libraries are loaded into memory.
Restrict mounting of untrusted remote filesystems (SMB, WebDAV, FTP) on end-user workstations until patches are deployed.

Patch Information

Red Hat has published a series of errata addressing CVE-2025-14512 across Red Hat Enterprise Linux 7, 8, 9, 10, and OpenShift 4. Refer to the Red Hat CVE page for CVE-2025-14512 for the authoritative advisory list, which includes RHSA-2026:15971, RHSA-2026:19361, RHSA-2026:19452, RHSA-2026:19457, RHSA-2026:19459, RHSA-2026:19460, RHSA-2026:19523, RHSA-2026:19524, RHSA-2026:19565, RHSA-2026:19567, RHSA-2026:21275, RHSA-2026:22634, RHSA-2026:25096, and RHSA-2026:29197. The upstream fix is tracked in GNOME GitLab Issue #3845.

Workarounds

Avoid opening files or browsing shares from untrusted sources with GNOME Files, GVfs, or other GIO-based applications until patches are applied.
Disable automatic thumbnailing and metadata extraction for network shares by adjusting gsettings keys such as org.gnome.nautilus.preferences show-image-thumbnails to never.
Where feasible, unmount untrusted remote filesystems and block outbound access to unknown WebDAV/SMB endpoints at the firewall.

bash

# Configuration example: identify vulnerable GLib packages and apply updates on RHEL
rpm -qa | grep -E '^glib2-'
sudo dnf --refresh update glib2

# Reduce exposure by disabling remote share thumbnailing in GNOME
gsettings set org.gnome.nautilus.preferences show-image-thumbnails 'never'
gsettings set org.gnome.desktop.thumbnailers disable-all true