CVE-2026-1417: Gpac Use-After-Free Vulnerability

CVE-2026-1417 Overview

A null pointer dereference vulnerability has been identified in GPAC, an open-source multimedia framework used for processing, packaging, and streaming multimedia content. The vulnerability exists in the dump_isom_rtp function within the file applications/mp4box/filedump.c in GPAC versions up to 2.4.0. This weakness can be exploited through local access to cause a denial of service condition by crashing the application.

Critical Impact

Local attackers can trigger a null pointer dereference in GPAC's MP4Box utility, leading to application crashes and potential denial of service for media processing workflows.

Affected Products

• GPAC versions up to and including 2.4.0
• MP4Box utility (part of GPAC multimedia framework)
• Systems using GPAC for media processing, packaging, or streaming

Discovery Timeline

• 2026-01-26 - CVE-2026-1417 published to NVD
• 2026-01-28 - Last updated in NVD database

Technical Details for CVE-2026-1417

Vulnerability Analysis

This vulnerability is classified as a Null Pointer Dereference (CWE-476) with an associated Improper Resource Shutdown or Release issue (CWE-404). The flaw resides in the dump_isom_rtp function, which is responsible for handling RTP hint track dumping operations within the MP4Box application.

The exploit has been publicly disclosed, meaning technical details are available that could enable malicious actors to reproduce the attack. The vulnerability requires local access to exploit, limiting the attack surface compared to remotely exploitable vulnerabilities. When triggered, the null pointer dereference causes the application to crash, resulting in denial of service for any ongoing media processing tasks.

Root Cause

The root cause stems from insufficient validation of pointer values before dereferencing them within the dump_isom_rtp function. When processing certain malformed or crafted input files, the function fails to verify that required pointers are valid before attempting to access the memory they reference. This missing validation check allows a null pointer to be dereferenced, causing an immediate application crash.

Attack Vector

The attack requires local access to the target system. An attacker would need to:

1. Craft a malicious media file designed to trigger the vulnerable code path
2. Have the ability to execute MP4Box or trigger its execution on the target system
3. Process the malicious file through the dump_isom_rtp functionality

The vulnerability is triggered during the processing of specially crafted input that causes the affected function to operate on invalid memory references.

The vulnerability manifests in the dump_isom_rtp function in applications/mp4box/filedump.c. When processing certain media files, the function fails to properly validate pointer values before dereferencing, leading to a crash. For technical details, see the GitHub Issue Discussion.

Detection Methods for CVE-2026-1417

Indicators of Compromise

• Unexpected crashes of MP4Box or GPAC-based applications during media file processing
• Segmentation fault errors in system logs referencing dump_isom_rtp or filedump.c
• Core dump files indicating null pointer access in GPAC components

Detection Strategies

• Monitor application logs for GPAC/MP4Box crash events with null pointer dereference signatures
• Implement file integrity monitoring on GPAC installations to detect unauthorized version downgrades
• Deploy endpoint detection rules that alert on abnormal termination of media processing applications
• Use application crash analysis tools to identify patterns consistent with this vulnerability

Monitoring Recommendations

• Configure crash reporting to capture and analyze GPAC application failures
• Monitor for unusual patterns of media file processing failures
• Track GPAC version deployments across the environment to identify vulnerable installations
• Implement logging for MP4Box command-line invocations to detect suspicious usage patterns

How to Mitigate CVE-2026-1417

Immediate Actions Required

• Upgrade GPAC to a patched version that includes commit f96bd57c3ccdcde4335a0be28cd3e8fe296993de
• Audit systems to identify all installations of GPAC versions 2.4.0 and earlier
• Restrict local access to systems running vulnerable GPAC versions
• Review and validate media files before processing with MP4Box utility

Patch Information

The GPAC development team has released a fix for this vulnerability. The patch is identified by commit hash f96bd57c3ccdcde4335a0be28cd3e8fe296993de and is available in the GPAC GitHub repository. Users should update to a version containing this fix or apply the patch manually to their GPAC installation.

For additional details on the vulnerability and patch, refer to the GitHub Issue Tracking.

Workarounds

• Limit access to MP4Box and GPAC utilities to trusted users only
• Implement input validation to screen media files before processing
• Run GPAC applications in sandboxed or containerized environments to limit crash impact
• Consider using alternative media processing tools until patching is complete

# Verify GPAC version and check for vulnerable installations
gpac -version
mp4box -version

# Apply the security patch from the official repository
cd /path/to/gpac/source
git fetch origin
git cherry-pick f96bd57c3ccdcde4335a0be28cd3e8fe296993de
make clean && make && make install