CVE-2026-120245 FFmpeg CVE debrief

Who should care

Defenders responsible for maintaining and securing systems that use FFmpeg should be aware of this vulnerability and take steps to verify and patch vulnerable systems. This includes reviewing and updating vulnerability management processes to ensure timely patching of vulnerable systems, monitoring systems for potential exploitation attempts, and reviewing compensating controls for exposed systems while remediation is scheduled and verified.

Why it matters

CVE-2026-120245 is a use of uninitialized resource vulnerability in FFmpeg's sunrast_decode_frame() function, affecting versions 0.10 through 9.0.2. Defenders should prioritize verifying FFmpeg versions and updating to patched versions if necessary.

• Potential exposure of sensitive data in decoded output
• Possible crashes or instability in FFmpeg applications
• Need for verification of FFmpeg versions and patching
• Potential for attackers to craft malicious Sun Raster files

Technical summary

The vulnerability is caused by the use of uninitialized resource in sunrast_decode_frame() function when decoding truncated 1-bit and 4-bit paletted Sun Raster images. This allows attackers to craft a truncated Sun Raster file, exposing stale heap contents in decoded output. The vulnerability affects FFmpeg versions 0.10 through 9.0.2 and has the potential to expose sensitive data in decoded output and cause crashes or instability in FFmpeg applications. Defenders should prioritize verifying FFmpeg versions and updating to patched versions if necessary.

Defensive priority

Defenders should prioritize verifying FFmpeg versions and updating to patched versions if necessary.

Recommended defensive actions

• Verify FFmpeg versions and update to patched versions if necessary
• Review and update vulnerability management processes to ensure timely patching of vulnerable systems
• Monitor systems for potential exploitation attempts
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability is caused by the use of uninitialized resource in sunrast_decode_frame() function when decoding truncated 1-bit and 4-bit paletted Sun Raster images. This allows attackers to craft a truncated Sun Raster file, exposing stale heap contents in decoded output. The source confidence is limited, and defenders should verify the vulnerability and patch vulnerable systems. Evidence is based on the official CVE record and NVD vulnerability assessment.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.