CVE-2026-125206: FFmpeg out-of-bounds read in ProRes

Summary

FFmpeg through 9.0.2 contains an out-of-bounds read vulnerability in the prores_ks encoder's get_alpha_data() that reads before the blocks buffer for interlaced frames with odd heights. Attackers can supply video with alpha and odd height encoded to interlaced ProRes 4444, causing out-of-bounds memory to be encoded into the output alpha plane.

cve.now Index

2Pcve.now Index 2 of 100 · methodology v3 · provisional

Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
Exposure?/25Unknown. No advisory context yet
Reach?/20Unknown. No tracked technology or package matched
Severity2/10CVSS 2.0
No patch0/5No signal

What would change the score

Would score about 57 if added to CISA KEV
Would score about 52 if CISA's SSVC rates exploitation active
Would score about 24 if advisories confirm default setups are exposed

How the score works · Rankings

What to do

Apply the patch listed under Evidence.

Timeline

Nov 9, 2026, 7:11 PM UTCCVE published
Nov 9, 2026, 7:15 PM UTCFirst seen by cve.now

Affected versions

FFmpeg FFmpeg
through 9.0.2

Evidence 5

Corrections

None so far.

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Questions about CVE-2026-125206

Is CVE-2026-125206 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data

Which versions are affected by CVE-2026-125206?

FFmpeg: through 9.0.2.Source: cve.now feed data

FFmpeg through 9.0.2 Out-of-Bounds Read via prores_ks Interlaced Alpha Encoding