CVE-2026-96546: GIMP DDS Loader Buffer Overflow Vulnerability

CVE-2026-96546 Overview

CVE-2026-96546 is a one-byte out-of-bounds heap read [CWE-125] in the file-dds plug-in shipped with the GNU Image Manipulation Program (GIMP). When a user opens a crafted uncompressed DirectDraw Surface (DDS) image, the loader performs an unconditional one-byte look-ahead after processing the final pixel. If the byte immediately following the pixel buffer sits on an inaccessible memory page, the plug-in crashes.

Critical Impact
The flaw is limited to a plug-in crash triggered by opening a malicious DDS file. No information disclosure or code execution has been demonstrated.

Affected Products

GNU Image Manipulation Program (GIMP)
GIMP file-dds plug-in (uncompressed DDS loader)
Downstream distributions packaging the affected GIMP build (see the Red Hat advisory)

Discovery Timeline

2026-09-23 - CVE-2026-96546 published to the National Vulnerability Database (NVD)
2026-09-23 - Last updated in the NVD database

Technical Details for CVE-2026-96546

Vulnerability Analysis

The file-dds plug-in decodes DDS pixel data sequentially. After writing the last pixel of an uncompressed image, the loader unconditionally reads one additional byte from the source buffer. This look-ahead is intended to support control flow inside the decode loop but is not gated by a bounds check against the pixel buffer length.

When the trailing byte lies within an allocated heap chunk, the read is silent and functionally harmless. When the byte sits on an unmapped page boundary, the process receives a segmentation fault and the plug-in terminates. The condition requires a local user to open a crafted DDS file, so exploitation depends on user interaction rather than remote delivery.

The impact is limited to availability of the GIMP plug-in process. No adjacent heap data is returned to the caller, and the read does not influence subsequent control flow in a way that has been shown to enable code execution.

Root Cause

The root cause is a missing boundary check on the terminating look-ahead read in the uncompressed DDS decode path. The loader assumes at least one addressable byte follows the final pixel, an assumption that does not hold when the pixel buffer ends on a page boundary. This is a classic [CWE-125] out-of-bounds read pattern.

Attack Vector

Exploitation requires a local user to open a malicious DDS file in GIMP. The attacker must deliver the file through email, download, or shared storage and convince the victim to open it. Successful triggering crashes the file-dds plug-in without affecting other running GIMP sessions of unrelated files.

No public proof-of-concept exploit or exploit code is available. Refer to the GNOME GIMP work item #16802 for upstream tracking of the fix.

Detection Methods for CVE-2026-96546

Indicators of Compromise

Unexpected termination of the file-dds plug-in process shortly after a user opens a DDS file.
Segmentation fault entries in system logs or core dumps referencing the GIMP DDS loader.
Delivery of DDS attachments from untrusted senders to workstations with GIMP installed.

Detection Strategies

Monitor endpoint telemetry for GIMP child process crashes correlated with .dds file access events.
Inspect mail and web gateways for DDS attachments originating from unverified sources.
Enable core dump collection on workstations running GIMP to support post-crash triage.

Monitoring Recommendations

Track GIMP version inventory across managed endpoints to identify unpatched installations.
Alert on repeated crashes of image-processing plug-ins on the same host, which may indicate targeted fuzzing or reconnaissance.
Correlate file open events for uncompressed DDS images with subsequent process exits to build a baseline for anomaly detection.

How to Mitigate CVE-2026-96546

Immediate Actions Required

Apply the fixed GIMP package from your distribution vendor once available; consult the Red Hat CVE-2026-96546 advisory for downstream status.
Restrict opening DDS files sourced from untrusted senders or unknown web downloads.
Communicate the low-severity availability risk to users who routinely process DDS assets.

Patch Information

Upstream tracking for the fix is available in GNOME GIMP work item #16802. Distribution-specific patch availability is tracked in the Red Hat Bug Report #2539601. Apply vendor updates as they are released.

Workarounds

Avoid opening DDS files from untrusted sources until the patched GIMP build is installed.
Convert DDS assets to another format using a non-GIMP tool if immediate processing is required.
Disable or remove the file-dds plug-in in environments that do not require DDS support.

bash

# Configuration example: remove the file-dds plug-in from a Linux GIMP install
# Adjust the path to match your distribution's GIMP plug-in directory.
sudo rm /usr/lib64/gimp/2.0/plug-ins/file-dds/file-dds