CVE-2026-125257
FFmpeg through 9.0.2 Heap Overflow via Nellymoser Encoder Trellis Search
CVSS Score
7.0
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-193 |
| Vendor | ffmpeg |
| Product | ffmpeg |
| Published | Nov 9, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H Attack Vector
Local
Attack Complexity
High
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
FFmpeg / FFmpeg
0 ≤ 9.0.2
References
code.ffmpeg.org: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24471 github.com: https://github.com/FFmpeg/FFmpeg/commit/733bec3e19759520ccdbeb6c3c0cae280bbe6dc5 github.com: https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/nellymoserenc.c#L262 github.com: https://github.com/FFmpeg/FFmpeg vulncheck.com: https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-heap-overflow-via-nellymoser-encoder-trellis-search
Credits
Zheng Yu 🔍 Joshua Rogers (AISLE Research) Michael Niedermayer