CVE-2026-125257

7.3 highEPSS 0.1%

High (7.3) in ffmpeg ffmpeg. EPSS 0.1% estimated probability of exploitation activity in the next 30 days.

FFmpeg through 9.0.2 contains an off-by-one heap overflow vulnerability in get_exponent_dynamic() in libavcodec/nellymoserenc.c that allows writing one element past the opt and path allocations. Attackers can supply crafted audio to applications encoding Nellymoser with trellis enabled, causing idx to equal OPT_SIZE and overwrite adjacent heap memory.

Severity

CVSS 4.0

7.3 high

CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

7.0 high

CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS: 0.1% estimated probability of exploitation activity in the next 30 days; 4th percentile. Scored 2026-11-10. A forecast for this CVE across the internet, not for your own systems.
CWE: CWE-193 Off-by-one Error
Published: 2026-11-09 20:18 UTC
NVD analysis: Awaiting analysis
Record from: the NVD, synced 2026-11-09 20:36 UTC

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Affected

ffmpeg:ffmpeg

Versions

From the CNA's record in the CVE List.

Product	Affected
FFmpeg	through 9.0.2

References

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