{"id":"CVE-2026-125199","kind":"vulnerability","aliases":["CVE-2026-125199"],"related":[],"title":"FFmpeg: crafted VC-1 video files exhaust memory in decoding applications","description":"FFmpeg through 9.0.2 contains a memory leak vulnerability in vc1_decode_frame() in libavcodec/vc1dec.c that leaks slice buffers when init_get_bits8() fails. Attackers can supply crafted files with repeated oversized VC-1 slices exceeding the bit reader limit to exhaust memory of decoding applications.","summary":"FFmpeg's VC-1 decoder in libavcodec leaks slice buffers when a bit reader initialization fails. An attacker who supplies a crafted VC-1 file with repeated oversized slices can exhaust the memory of any application decoding it.","severity":"medium","cvss":6.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["ffmpeg","libavcodec","media-processing","package"],"not_affected_if":["no-untrusted-media","vc1-not-decoded"],"how_to_check":"- Check the installed FFmpeg version with `ffmpeg -version`, comparing against the product range in the sources (through 9.0.2).\n- Find applications that decode untrusted VC-1 media through libavcodec, such as media servers or transcoders.","fix":null,"status":"open","published_at":"2026-11-09T19:16:56+00:00","first_seen_at":"2026-11-09T19:28:18+00:00","triaged_at":"2026-11-09T19:31:30+00:00","updated_at":"2026-11-09T19:31:30+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-09T19:31:30Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"unknown","title":"FFmpeg: crafted VC-1 video files exhaust memory in decoding applications","impact":"low","summary":"FFmpeg's VC-1 decoder in libavcodec leaks slice buffers when a bit reader initialization fails. An attacker who supplies a crafted VC-1 file with repeated oversized slices can exhaust the memory of any application decoding it.","audience":"businesses","category":"package","nicknames":[],"who_cares":["ffmpeg","libavcodec","media-processing"],"confidence":0.6,"fix_status":"unknown","needs_auth":"no","worst_case":"Memory exhaustion crashes the decoding application.","analyst_note":"Confirm the fixed version from the linked GitHub patch and the vulncheck advisory; the sources do not state one.","how_to_check":"- Check the installed FFmpeg version with `ffmpeg -version`, comparing against the product range in the sources (through 9.0.2).\n- Find applications that decode untrusted VC-1 media through libavcodec, such as media servers or transcoders.","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-untrusted-media","vc1-not-decoded"],"who_is_affected":"Applications that link libavcodec and decode VC-1 media from untrusted sources can be driven to exhaust memory. Systems that only process trusted media or do not decode VC-1 are less exposed. The sources do not name a fixed version; the linked patch is the only fix reference.","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000745,"input_tokens":4628,"output_tokens":565,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-1':4A,27B,47B,93C '-125199':14A,17A '-2026':13A,16A '9.0.2':63C 'applic':11A,59B,105C 'attack':41B,84C 'bit':36B,97C 'bits8':82C 'buffer':33B,78C 'contain':64C 'craft':2A,45B,87C 'cve':12A,15A 'decod':10A,28B,60B,71C,104C 'exceed':95C 'exhaust':7A,54B,101C 'fail':39B,83C 'ffmpeg':1A,18B,24B,61C 'file':6A,48B,88C 'frame':72C 'get':81C 'init':80C 'initi':38B 'leak':31B,67C,76C 'libavcodec':19B,30B 'libavcodec/vc1dec.c':74C 'limit':99C 'media':21B 'media-process':20B 'memori':8A,56B,66C,102C 'overs':51B,91C 'packag':23B 'process':22B 'reader':37B,98C 'repeat':50B,90C 'slice':32B,52B,77C,94C 'suppli':43B,86C 'vc':3A,26B,46B,92C 'vc1':70C 'video':5A 'vulner':68C","nicknames":[],"mitigations":[],"who_affected":"Applications that link libavcodec and decode VC-1 media from untrusted sources can be driven to exhaust memory. Systems that only process trusted media or do not decode VC-1 are less exposed. The sources do not name a fixed version; the linked patch is the only fix reference.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["ffmpeg","libavcodec","mediaprocessing","medium","package"],"campaign_type":null,"search_a":"'-1':4A '-125199':14A,17A '-2026':13A,16A 'applic':11A 'craft':2A 'cve':12A,15A 'decod':10A 'exhaust':7A 'ffmpeg':1A 'file':6A 'memori':8A 'vc':3A 'video':5A","search_b":"'-1':27B,47B 'applic':59B 'attack':41B 'bit':36B 'buffer':33B 'craft':45B 'decod':28B,60B 'exhaust':54B 'fail':39B 'ffmpeg':18B,24B 'file':48B 'initi':38B 'leak':31B 'libavcodec':19B,30B 'media':21B 'media-process':20B 'memori':56B 'overs':51B 'packag':23B 'process':22B 'reader':37B 'repeat':50B 'slice':32B,52B 'suppli':43B 'vc':26B,46B","search_c":"'-1':93C '9.0.2':63C 'applic':105C 'attack':84C 'bit':97C 'bits8':82C 'buffer':78C 'contain':64C 'craft':87C 'decod':71C,104C 'exceed':95C 'exhaust':101C 'fail':83C 'ffmpeg':61C 'file':88C 'frame':72C 'get':81C 'init':80C 'leak':67C,76C 'libavcodec/vc1dec.c':74C 'limit':99C 'memori':66C,102C 'overs':91C 'reader':98C 'repeat':90C 'slice':77C,94C 'suppli':86C 'vc':92C 'vc1':70C 'vulner':68C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-09T19:16:56+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/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-2026-125199","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-125199","severity":null,"published_at":"2026-11-09T19:16:56+00:00","modified_at":"2026-11-09T19:16:56+00:00","first_seen_at":"2026-11-09T19:28:18+00:00","fetched_at":"2026-11-09T19:28:18+00:00","note":null}],"documents":[{"id":109289,"url":"https://github.com/FFmpeg/FFmpeg/commit/afdc555aace698b88c86d3f33a7773a6c8ba2897","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":109290,"url":"https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-memory-leak-in-vc-1-decoder-via-vc1-decode-frame","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"}