{"affected":[{"defaultStatus":"unaffected","ecosystem":"github","packageName":"ffmpeg/ffmpeg","product":"FFmpeg","source":"CNA: VulnCheck","vendor":"FFmpeg","versions":[{"lessThanOrEqual":"9.0.2","status":"affected","version":"0","versionType":"semver"}]}],"cveId":"CVE-2026-125257","cwes":["CWE-193"],"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.","epss":{"date":"2026-11-13","percentile":0.03661,"score":0.00143},"exploits":[],"kev":null,"metrics":[{"score":7.3,"severity":"high","source":"CNA: VulnCheck","vector":"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","version":"4.0"},{"score":7,"severity":"high","source":"CNA: VulnCheck","vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","version":"3.1"},{"score":7.3,"severity":"high","source":"NVD: disclosure@vulncheck.com","vector":"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/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","version":"4.0"},{"score":7,"severity":"high","source":"NVD: disclosure@vulncheck.com","vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","version":"3.1"}],"modifiedAt":1794622316493,"publishedAt":1794251521153,"references":[{"source":"CNA: VulnCheck","tags":["issue-tracking"],"url":"https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24471"},{"source":"CNA: VulnCheck","tags":["patch"],"url":"https://github.com/FFmpeg/FFmpeg/commit/733bec3e19759520ccdbeb6c3c0cae280bbe6dc5"},{"source":"CNA: VulnCheck","tags":["technical-description"],"url":"https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/nellymoserenc.c#L262"},{"source":"CNA: VulnCheck","tags":["product"],"url":"https://github.com/FFmpeg/FFmpeg"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-heap-overflow-via-nellymoser-encoder-trellis-search"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24471"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/FFmpeg/FFmpeg"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/nellymoserenc.c#L262"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/FFmpeg/FFmpeg/commit/733bec3e19759520ccdbeb6c3c0cae280bbe6dc5"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-heap-overflow-via-nellymoser-encoder-trellis-search"}],"remediation":[{"kind":"fix","source":"CNA: VulnCheck","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/FFmpeg/FFmpeg/commit/733bec3e19759520ccdbeb6c3c0cae280bbe6dc5"}],"revision":"efeca2184c2a5c3fd9b3e296db50e632acce0f257ddd1995268132bdfa3dfa71","sources":[{"modifiedAt":1794622316493,"name":"CNA: VulnCheck","retrievedAt":1794625747567,"url":"https://www.cve.org/CVERecord?id=CVE-2026-125257"},{"modifiedAt":1794347193920,"name":"NVD","retrievedAt":1794356436393,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-125257"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1794625769425,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-125257"}],"ssvc":{"assessedAt":1794622306079,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"total"},"status":"published","title":"FFmpeg through 9.0.2 Heap Overflow via Nellymoser Encoder Trellis Search","updatedAt":1794625769425}