CVE-2025-60471: Use-After-Free in GPAC MP4Box Before 26.02.0 Denial of Service

Technical summary

The vulnerability exists in the gf_filter_pid_reconfigure_task_discard function within /filter_core/filter_pid.c of GPAC versions prior to 26.02.0. It is a classic use-after-free (CWE-416) condition where freed memory is dereferenced during the filter reconfiguration task cleanup process. When a crafted media file is supplied as input, the parser triggers a sequence of operations that cause the function to reference memory that has already been released. This leads to undefined behavior and typically results in a crash of the MP4Box process. The vulnerability requires local file system access and user interaction (opening the file), which limits the immediate attack surface but remains significant in environments where users routinely process untrusted media files.

Business impact

Organizations using GPAC's MP4Box for media processing pipelines—such as broadcast facilities, content management systems, video transcoding services, and multimedia research labs—face availability risk. A crafted media file distributed internally or obtained from third parties could crash processing jobs, disrupting batch workflows and delaying time-sensitive content delivery. In environments where MP4Box is integrated into automated systems, denial of service could cascade to dependent processes. The impact is typically limited to availability; there is no confidentiality or integrity compromise. However, the ease of weaponization via malicious media files and the likelihood of user interaction (opening files sent by collaborators or downloaded from public sources) elevates this beyond theoretical risk in many organizational contexts.

Affected systems

GPAC Project's MP4Box versions before 26.02.0 are affected. This includes all stable and development releases prior to that version number. The vulnerability does not affect other GPAC utilities or third-party applications unless they directly embed the vulnerable filter_core code from GPAC. Users should verify their installed version by running `MP4Box -version` and comparing against the patched release. Organizations should audit media processing systems, transcoding servers, and any custom applications built on the GPAC library to determine exposure.

Exploitability

Exploitation requires two conditions: a user must have MP4Box installed locally, and they must open a crafted media file with it. There is no network vector; the attacker cannot remotely trigger the crash. The barrier to exploitation is relatively low from an attacker's perspective—creating a malicious media file requires understanding GPAC's parser logic, but proof-of-concept development is within reach of competent fuzzing or reverse-engineering efforts. The user interaction requirement (opening the file) is the primary mitigation; users who do not process untrusted media files are not at risk. However, in collaborative or content-ingestion environments, this assumption is often unreliable. The CVSS score of 5.5 (MEDIUM) reflects the local attack vector, requirement for user interaction, and the limitation of the impact to availability only.

Remediation

Upgrade GPAC Project and MP4Box to version 26.02.0 or later. This version includes a fix for the use-after-free condition in the filter configuration logic. Organizations should test the upgrade in a non-production environment first to ensure compatibility with any dependent media processing workflows. Verify the patched version using `MP4Box -version` and confirm that automated media ingestion and transcoding pipelines continue to operate correctly after the update.

Patch guidance

The patch is available in GPAC version 26.02.0 and all subsequent releases. Check the official GPAC repository (https://github.com/gpac/gpac) for release notes and download links. For users on older versions, verify against the vendor advisory or release notes to confirm the specific fix address the CWE-416 condition in filter_pid.c. If you are using GPAC as a library integrated into a custom application, ensure you rebuild your application with the patched GPAC library version. For Linux distribution packages (e.g., via apt, yum), check if your package maintainer has released updated versions; if not, consider updating from the official GPAC sources.

Detection guidance

Monitor MP4Box process crashes and exits with status codes indicating segmentation faults or memory errors (SIGSEGV, SIGABRT). Log files from media processing pipelines should be reviewed for unexpected terminations. If using centralized logging, search for crash reports or core dumps containing references to gf_filter_pid_reconfigure_task_discard. Review system logs for file access patterns—identify when untrusted or external media files are processed. Consider implementing integrity checks on media files before passing them to MP4Box (e.g., validate file structure or use a sandboxed preview tool). Intrusion detection signatures targeting malformed media file structures may provide early warning of attack attempts, though specificity is limited without deep packet inspection into media formats.

Why prioritize this

While the CVSS score is MEDIUM (5.5), prioritize this vulnerability if your organization routinely processes media files from external sources, operates a media ingestion or transcoding service, or uses MP4Box in mission-critical workflows. The combination of ease-of-exploitation (crafted file) and high likelihood of user interaction in media-centric environments makes this a practical risk. The absence of KEV (Known Exploited Vulnerability) status suggests limited active exploitation in the wild as of the publication date, which may provide a window for patching before widespread abuse. Conversely, if MP4Box is only used internally by trusted developers or in isolated environments, this can be addressed in the next regular maintenance cycle.

Risk score, explained

CVSS 3.1 score of 5.5 (MEDIUM) is derived from: Attack Vector = Local (the file must be on the system), Attack Complexity = Low (no special conditions beyond the crafted file), Privileges Required = None (any user can trigger it), User Interaction = Required (the user must open the file), Scope = Unchanged (no impact outside the vulnerable component), and Confidentiality/Integrity/Availability = None/None/High (denial of service only). The score appropriately weights the practical constraints (local + user interaction) against the ease of exploitation and the severity of the denial-of-service impact. It does not account for secondary impacts such as workflow disruption or data loss due to cascading failures, which may elevate perceived risk in certain deployment contexts.

Frequently asked questions