FFmpeg NULL Pointer Dereference in libavcodec Enables Crash via Crafted Media Files

Security researcher Alexander A. Shvedov disclosed a vulnerability in FFmpeg that allows remote attackers to crash the application by processing a specially crafted media file. The flaw, identified as CVE-2025-52290, stems from a NULL pointer dereference within the avpriv_h264_has_num_reorder_frames function. According to the advisory posted to the oss-security mailing list, this defect is associated with the FFmpeg product, which includes libavcodec and libavformat, widely used for decoding and multiplexing video content in various enterprise and consumer applications.

The risk

The Common Vulnerability Scoring System version 3.1 rates this flaw as high severity with a score of 7.5, according to CISA-ADP metrics. The vector string AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H indicates that the attack can be launched remotely with low complexity and no user interaction required. While the breach does not compromise confidentiality or integrity, it achieves high availability impact by causing the target application to terminate unexpectedly. This makes the vulnerability particularly dangerous for automated media processing pipelines that handle untrusted input without robust error handling or service recovery mechanisms.

Who is exposed

Organizations using FFmpeg version N-119856-gbe46370941 are explicitly exposed to this threat. The advisory identifies commit be46370941405fb04402d96373a53e2a1846f3ac as the affected codebase marker. Any system that relies on this specific build for video transcoding, streaming, or playback is at risk. Users who have compiled FFmpeg from source using this revision or are running package versions derived from this commit hash must verify their installations against this vulnerability.

Cost and compliance

The source material does not specify financial costs or regulatory compliance implications associated with CVE-2025-52290. The advisory focuses solely on the technical classification of the NULL pointer dereference and the affected software versions. There is no mention of data breach liabilities, insurance impacts, or specific compliance frameworks such as GDPR or HIPAA being triggered by this availability issue. Security teams should evaluate their own internal service level agreements and business continuity requirements to determine the operational impact of such a crash.

What to watch

Security operations teams should prioritize verifying the FFmpeg version running on all media processing servers and edge devices. Administrators must check whether their deployment matches the affected commit hash or version string to determine exposure. Monitoring for unexpected service restarts or crash logs in video processing applications can help identify exploitation attempts before they cause widespread disruption.

Signals worth monitoring

Teams usually detect this type of availability attack by observing sudden process terminations in video processing services without corresponding application errors. Check whether system logs show core dumps or SIGSEGV signals immediately after handling new media files. Monitor for spikes in service restart counts or health check failures on transcoding nodes. Containment moves typically involve isolating the affected service, disabling the ingestion of untrusted media, and reviewing recent input files for anomalies. Verify that logging captures the file hash or metadata of processed inputs to aid in forensic analysis.

What to do and how to stay safe: FFmpeg

• Inventory all systems running FFmpeg and verify their version against the affected commit be46370941405fb04402d96373a53e2a1846f3ac.
• Restrict media processing services to trusted inputs only until a patched version is available and deployed.
• Monitor system logs for unexpected FFmpeg crashes or high availability alerts indicating service disruption.
• Prepare incident response procedures for rapid service restart and isolation of affected nodes.

Step-by-step guide: Vulnerability Prioritization: Fix What Actually Matters First

General security guidance from the SecOps Signal newsroom. It is not confirmed advice from the organisations named in this story.

Frequently asked questions

What is the CVSS score for CVE-2025-52290?

The CVSS 3.1 score is 7.5, which is classified as high severity.

Which FFmpeg components are affected by this vulnerability?

The vulnerability affects FFmpeg, specifically the libavcodec and libavformat libraries.

Is there a patch available for CVE-2025-52290?

No fix has been confirmed yet in the provided source material.