{"id":"CVE-2026-125171","kind":"vulnerability","aliases":["CVE-2026-125171"],"related":[],"title":"FFmpeg: crafted Musepack SV7 file reads past audio buffer","description":"FFmpeg through 9.0.2 contains an out-of-bounds read vulnerability in the Musepack SV7 decoder because mpc7_decode_init() does not validate lastframelen against MPC_FRAME_SIZE. Attackers can supply a crafted Musepack SV7 file declaring an oversized final frame, causing consumers of decoded frames to read past the audio buffer, leading to crashes or heap memory disclosure.","summary":"FFmpeg's Musepack SV7 decoder does not check the declared size of the final frame, so a crafted file makes it read past the audio buffer. An attacker can crash a program that decodes the file or leak heap memory.","severity":"medium","cvss":6.9,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["ffmpeg","media-processing","package","self-hosted"],"not_affected_if":["no-musepack-input","trusted-files-only"],"how_to_check":"- Run `ffmpeg -version` and compare against the fixed release named in the linked patch.\n- Check whether your application decodes user-supplied Musepack (.mpc) files through FFmpeg.","fix":null,"status":"open","published_at":"2026-11-09T19:16:51+00:00","first_seen_at":"2026-11-09T19:28:16+00:00","triaged_at":"2026-11-09T19:30:22+00:00","updated_at":"2026-11-09T19:30:22+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-09T19:30:22Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"unknown","title":"FFmpeg: crafted Musepack SV7 file reads past audio buffer","impact":"medium","summary":"FFmpeg's Musepack SV7 decoder does not check the declared size of the final frame, so a crafted file makes it read past the audio buffer. An attacker can crash a program that decodes the file or leak heap memory.","audience":"businesses","category":"package","nicknames":[],"who_cares":["ffmpeg","media-processing","self-hosted"],"confidence":0.6,"fix_status":"unknown","needs_auth":"no","worst_case":"crash or heap memory disclosure from a crafted file","analyst_note":"Confirm the fixed FFmpeg version and patch commit from the linked GitHub patch and the VulnCheck advisory.","how_to_check":"- Run `ffmpeg -version` and compare against the fixed release named in the linked patch.\n- Check whether your application decodes user-supplied Musepack (.mpc) files through FFmpeg.","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-musepack-input","trusted-files-only"],"who_is_affected":"Applications that pass untrusted Musepack SV7 files to FFmpeg for decoding, such as media converters, upload-processing pipelines and thumbnailers. Systems that only decode trusted local files or never handle Musepack can skip it. The sources do not name a fixed version.","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000733,"input_tokens":4641,"output_tokens":538,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-125171':12A,15A '-2026':11A,14A '9.0.2':66C 'attack':51B,92C 'audio':8A,48B,114C 'bound':72C 'buffer':9A,49B,115C 'caus':105C 'check':31B 'consum':106C 'contain':67C 'craft':2A,41B,96C 'crash':53B,118C 'cve':10A,13A 'declar':33B,100C 'decod':28B,57B,79C,82C,108C 'disclosur':122C 'ffmpeg':1A,16B,24B,64C 'file':5A,42B,59B,99C 'final':37B,103C 'frame':38B,90C,104C,109C 'heap':62B,120C 'host':23B 'init':83C 'lastframelen':87C 'lead':116C 'leak':61B 'make':43B 'media':18B 'media-process':17B 'memori':63B,121C 'mpc':89C 'mpc7':81C 'musepack':3A,26B,77C,97C 'out-of-bound':69C 'overs':102C 'packag':20B 'past':7A,46B,112C 'process':19B 'program':55B 'read':6A,45B,73C,111C 'self':22B 'self-host':21B 'size':34B,91C 'suppli':94C 'sv7':4A,27B,78C,98C 'valid':86C 'vulner':74C","nicknames":[],"mitigations":[],"who_affected":"Applications that pass untrusted Musepack SV7 files to FFmpeg for decoding, such as media converters, upload-processing pipelines and thumbnailers. Systems that only decode trusted local files or never handle Musepack can skip it. The sources do not name a fixed version.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["ffmpeg","mediaprocessing","medium","package","selfhosted"],"campaign_type":null,"search_a":"'-125171':12A,15A '-2026':11A,14A 'audio':8A 'buffer':9A 'craft':2A 'cve':10A,13A 'ffmpeg':1A 'file':5A 'musepack':3A 'past':7A 'read':6A 'sv7':4A","search_b":"'attack':51B 'audio':48B 'buffer':49B 'check':31B 'craft':41B 'crash':53B 'declar':33B 'decod':28B,57B 'ffmpeg':16B,24B 'file':42B,59B 'final':37B 'frame':38B 'heap':62B 'host':23B 'leak':61B 'make':43B 'media':18B 'media-process':17B 'memori':63B 'musepack':26B 'packag':20B 'past':46B 'process':19B 'program':55B 'read':45B 'self':22B 'self-host':21B 'size':34B 'sv7':27B","search_c":"'9.0.2':66C 'attack':92C 'audio':114C 'bound':72C 'buffer':115C 'caus':105C 'consum':106C 'contain':67C 'craft':96C 'crash':118C 'declar':100C 'decod':79C,82C,108C 'disclosur':122C 'ffmpeg':64C 'file':99C 'final':103C 'frame':90C,104C,109C 'heap':120C 'init':83C 'lastframelen':87C 'lead':116C 'memori':121C 'mpc':89C 'mpc7':81C 'musepack':77C,97C 'out-of-bound':69C 'overs':102C 'past':112C 'read':73C,111C 'size':91C 'suppli':94C 'sv7':78C,98C 'valid':86C 'vulner':74C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-09T19:16:51+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/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","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-125171","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-125171","severity":null,"published_at":"2026-11-09T19:16:51+00:00","modified_at":"2026-11-09T19:16:51+00:00","first_seen_at":"2026-11-09T19:28:16+00:00","fetched_at":"2026-11-09T19:28:16+00:00","note":null}],"documents":[{"id":109229,"url":"https://github.com/FFmpeg/FFmpeg/commit/5d59b7c45d7142bddd13ddc8891e72c5c7dc991b","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":109230,"url":"https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-out-of-bounds-read-in-musepack-sv7-decoder-via-mpc7-c","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"}