CVE-2026-125209FFmpeg FFmpeg
NVD
Vulnerability Summary
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.
CVSS v4.0 Base Metrics — Score 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:NAttack VectorLocal
Attack ComplexityLow
Attack RequirementsNone
Privileges RequiredNone
User InteractionPassive
Confidentiality (Vulnerable System)High
Integrity (Vulnerable System)High
Availability (Vulnerable System)High
Confidentiality (Subsequent System)None
Integrity (Subsequent System)None
Availability (Subsequent System)None
Show CVSS v3.x metrics (score 7.8)
CVSS v3.1 Base Metrics — Score 7.8 (HIGH)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HAttack VectorLocal
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
Affected & Patched Versions
- FFmpeg FFmpeg < 8.1.3
- FFmpeg FFmpeg >= 9.0 and < 9.0.2
- FFmpeg FFmpeg 8.1.3
- FFmpeg FFmpeg 9.0.2
What to do
Plan remediation soon. No exploitation is confirmed yet, but the severity is high.
- Check whether you run FFmpeg FFmpeg and which version.
- Update to a patched version listed above, then confirm the new version.
Timeline
- Nov 9, 2026Published
- Nov 9, 2026Record last modified
Score, severity and exploitation changes are tracked from the day Watchtower started logging them.
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Set up CVE alertsExternal References
- Referencehttps://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24486
- Patchhttps://github.com/FFmpeg/FFmpeg/commit/8702f12c9daa199cc4d7c17164b13c3cdcdc2436
- Referencehttps://github.com/FFmpeg/FFmpeg/blob/n9.0.1/libavcodec/dvdsubenc.c#L344
- Referencehttps://github.com/FFmpeg/FFmpeg
- Referencehttps://www.vulncheck.com/advisories/ffmpeg-before-8.1.3-and-9-x-before-9.0.2-heap-buffer-overflow-via-dvdsubenc-c
Data last checked: Nov 13, 2026 21:28 UTC