Vulnerability record
CVE-2026-125209
The short answer
CVE-2026-125209 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 before 8.1.3 and 9.x before 9.0.2 contains a heap buffer overflow vulnerability in the DVD subtitle encoder that underestimates RLE output size for odd-width rectangles. Attackers can supply files with crafted bitmap subtitles that, when transcoded to the dvdsub encoder, write past the output buffer and corrupt 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
- code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24486
- github.com/FFmpeg/FFmpeg
- github.com/FFmpeg/FFmpeg/blob/n9.0.1/libavcodec/dvdsubenc.c#L344
- github.com/FFmpeg/FFmpeg/commit/8702f12c9daa199cc4d7c17164b13c3cdcdc2436
- www.vulncheck.com/advisories/ffmpeg-before-8.1.3-and-9-x-before-9.0.2-heap-buffer-overflow-via-dvdsubenc-c
Questions
Is CVE-2026-125209 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-2026-125209?
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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