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Vulnerability record

CVE-2026-125233

highCVSS 4.0 8.5EPSS 0.14%Published · FFmpeg

The short answer

CVE-2026-125233 affects FFmpeg FFmpeg and is rated high (CVSS 8.5). It is not in CISA's KEV catalog; EPSS puts the chance of exploitation in the next 30 days at 0.14%.

What it is

FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in dvbsub_encode() in libavcodec/dvbsubenc.c that undercounts each CLUT segment header by two bytes. Attackers can supply a file with many bitmap subtitle rectangles that, when transcoded to the dvbsub encoder, writes past the output buffer and corrupts heap memory.

Weakness: CWE-131.

Severity

8.5 high

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Exploited (CISA KEV)

Not listed

CISA lists confirmed exploitation only

EPSS, next 30 days

0.14%

Higher than 3% of scored CVEs

How it can be exploited

Attack vector
Local
Attack complexity
Low
Attack requirements
None
Privileges required
None
User interaction
Passive
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Affected products

FFmpeg. NVD's record lists the exact affected versions.

References

Questions

Is CVE-2026-125233 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog as of 2026-11-11. FIRST's EPSS estimates a 0.14% chance of exploitation in the next 30 days.

How do I fix CVE-2026-125233?

Follow the vendor advisory in the references below. NVD lists the affected versions under its configurations.

From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Awaiting Analysis. The description is NVD's text, quoted as published.

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