{"id":"CVE-2026-125195","kind":"vulnerability","aliases":["CVE-2026-125195"],"related":[],"title":"FFmpeg: uninitialized heap memory leaks into ADPCM_MS encoded audio output","description":"FFmpeg through 9.0.2 contains an uninitialized memory disclosure vulnerability in adpcm_encode_frame() in libavcodec/adpcmenc.c that leaks heap bytes when encoding mono ADPCM_MS audio with trellis enabled. Attackers submitting audio to a service using this encoding receive output packets where about half of each block contains stale heap memory from the encoding process.","summary":"FFmpeg through 9.0.2 has an uninitialized memory bug in the ADPCM encoder that leaks heap bytes when encoding mono ADPCM_MS audio with trellis enabled. An attacker who submits audio to a service that encodes this way can read stale heap memory from the encoded output.","severity":"low","cvss":2.5,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["audio-transcoding","ffmpeg","libavcodec","package"],"not_affected_if":["no-adpcm-ms-encoding","no-user-submitted-audio"],"how_to_check":"- Check the installed FFmpeg version with `ffmpeg -version`; versions through `9.0.2` are described as affected.\n- Look for services that encode audio with `-c:a adpcm_ms` and trellis enabled, such as user-uploaded audio transcoding pipelines.","fix":null,"status":"open","published_at":"2026-11-09T19:16:55+00:00","first_seen_at":"2026-11-09T19:28:17+00:00","triaged_at":"2026-11-09T19:33:44+00:00","updated_at":"2026-11-09T19:33:44+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-09T19:33:44Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"internet","title":"FFmpeg: uninitialized heap memory leaks into ADPCM_MS encoded audio output","impact":"low","summary":"FFmpeg through 9.0.2 has an uninitialized memory bug in the ADPCM encoder that leaks heap bytes when encoding mono ADPCM_MS audio with trellis enabled. An attacker who submits audio to a service that encodes this way can read stale heap memory from the encoded output.","audience":"developers","category":"package","nicknames":[],"who_cares":["ffmpeg","libavcodec","audio-transcoding"],"confidence":0.6,"fix_status":"unknown","needs_auth":"no","worst_case":"heap memory contents leak into encoded audio output","analyst_note":"Check the Patch link on github.com for the fixed FFmpeg version and whether trellis is enabled by default; the NVD text alone does not give a fix.","how_to_check":"- Check the installed FFmpeg version with `ffmpeg -version`; versions through `9.0.2` are described as affected.\n- Look for services that encode audio with `-c:a adpcm_ms` and trellis enabled, such as user-uploaded audio transcoding pipelines.","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-adpcm-ms-encoding","no-user-submitted-audio"],"who_is_affected":"Only services that run FFmpeg's ADPCM_MS encoder with trellis enabled on audio that users can submit and receive back. Sources do not say whether default settings trigger it. Systems that only decode audio or never encode ADPCM_MS are likely unaffected.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"yes","severity_if_unknown":"low"},"cost_usd":0.000768,"input_tokens":4632,"output_tokens":610,"severity_before":"low"},"analyst_status":null,"analyst_note":null,"search":"'-125195':14A,17A '-2026':13A,16A '9.0.2':26B,72C 'adpcm':7A,34B,43B,80C,92C 'attack':50B,98C 'audio':10A,19B,45B,53B,94C,100C 'audio-transcod':18B 'block':115C 'bug':31B 'byte':39B,88C 'contain':73C,116C 'cve':12A,15A 'disclosur':77C 'enabl':48B,97C 'encod':9A,35B,41B,58B,68B,81C,90C,106C,122C 'ffmpeg':1A,21B,24B,70C 'frame':82C 'half':112C 'heap':3A,38B,64B,87C,118C 'leak':5A,37B,86C 'libavcodec':22B 'libavcodec/adpcmenc.c':84C 'memori':4A,30B,65B,76C,119C 'mono':42B,91C 'ms':8A,44B,93C 'output':11A,69B,108C 'packag':23B 'packet':109C 'process':123C 'read':62B 'receiv':107C 'servic':56B,103C 'stale':63B,117C 'submit':52B,99C 'transcod':20B 'trelli':47B,96C 'uniniti':2A,29B,75C 'use':104C 'vulner':78C 'way':60B","nicknames":[],"mitigations":[],"who_affected":"Only services that run FFmpeg's ADPCM_MS encoder with trellis enabled on audio that users can submit and receive back. Sources do not say whether default settings trigger it. Systems that only decode audio or never encode ADPCM_MS are likely unaffected.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["audiotranscoding","ffmpeg","libavcodec","low","package"],"campaign_type":null,"search_a":"'-125195':14A,17A '-2026':13A,16A 'adpcm':7A 'audio':10A 'cve':12A,15A 'encod':9A 'ffmpeg':1A 'heap':3A 'leak':5A 'memori':4A 'ms':8A 'output':11A 'uniniti':2A","search_b":"'9.0.2':26B 'adpcm':34B,43B 'attack':50B 'audio':19B,45B,53B 'audio-transcod':18B 'bug':31B 'byte':39B 'enabl':48B 'encod':35B,41B,58B,68B 'ffmpeg':21B,24B 'heap':38B,64B 'leak':37B 'libavcodec':22B 'memori':30B,65B 'mono':42B 'ms':44B 'output':69B 'packag':23B 'read':62B 'servic':56B 'stale':63B 'submit':52B 'transcod':20B 'trelli':47B 'uniniti':29B 'way':60B","search_c":"'9.0.2':72C 'adpcm':80C,92C 'attack':98C 'audio':94C,100C 'block':115C 'byte':88C 'contain':73C,116C 'disclosur':77C 'enabl':97C 'encod':81C,90C,106C,122C 'ffmpeg':70C 'frame':82C 'half':112C 'heap':87C,118C 'leak':86C 'libavcodec/adpcmenc.c':84C 'memori':76C,119C 'mono':91C 'ms':93C 'output':108C 'packet':109C 'process':123C 'receiv':107C 'servic':103C 'stale':117C 'submit':99C 'trelli':96C 'uniniti':75C 'use':104C 'vulner':78C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-09T19:16:55+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/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","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-125195","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-125195","severity":null,"published_at":"2026-11-09T19:16:55+00:00","modified_at":"2026-11-09T19:16:55+00:00","first_seen_at":"2026-11-09T19:28:17+00:00","fetched_at":"2026-11-09T19:28:17+00:00","note":null}],"documents":[{"id":109281,"url":"https://github.com/FFmpeg/FFmpeg/commit/fb13409aaffc151f602ad357db46052e98ea46e8","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":109282,"url":"https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-uninitialized-memory-disclosure-via-adpcm-ms-trellis-encoding","title":"Third-party advisory: www.vulncheck.com","kind":"advisory","source":"nvd","publisher":"research","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Third-party advisory: www.vulncheck.com"}],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}