{"id":"CVE-2026-125257","published":"2026-11-09T20:18:11.930","lastModified":"2026-11-10T21:46:33.920","description":"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.","cvssScore":7,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","cwes":["CWE-193"],"vendors":[],"products":[],"references":[{"url":"https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24471","tags":[]},{"url":"https://github.com/FFmpeg/FFmpeg","tags":[]},{"url":"https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/nellymoserenc.c#L262","tags":[]},{"url":"https://github.com/FFmpeg/FFmpeg/commit/733bec3e19759520ccdbeb6c3c0cae280bbe6dc5","tags":[]},{"url":"https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-heap-overflow-via-nellymoser-encoder-trellis-search","tags":[]}],"exploitRefs":[{"url":"https://github.com/FFmpeg/FFmpeg","tags":[]},{"url":"https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/nellymoserenc.c#L262","tags":[]},{"url":"https://github.com/FFmpeg/FFmpeg/commit/733bec3e19759520ccdbeb6c3c0cae280bbe6dc5","tags":[]}],"hasPoc":true,"ai":null}