{"id":"CVE-2026-125246","kind":"vulnerability","aliases":["CVE-2026-125246"],"related":[],"title":"FFmpeg: crafted JPEG stream crashes the process via miscounted stuffing bytes","description":"FFmpeg through 9.0.2 contains a denial of service vulnerability in cbs_jpeg_assemble_fragment() that miscounts 0xff stuffing bytes in JPEG scan headers. Attackers can supply a crafted JPEG/MJPEG stream with 0xff in the scan header, triggering an av_assert0 abort when CBS-based bitstream filters process it.","summary":"FFmpeg through 9.0.2 miscounts 0xff stuffing bytes in JPEG scan headers in cbs_jpeg_assemble_fragment(). A crafted JPEG or MJPEG stream triggers an av_assert0 abort, so an attacker can crash any process that processes the file.","severity":"medium","cvss":5.7,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["ffmpeg","media-processing","package","self-hosted"],"not_affected_if":["no-untrusted-media","not-using-cbs-filters"],"how_to_check":"- Check the installed FFmpeg version with `ffmpeg -version`\n- Look for FFmpeg in services that decode or transcode user-supplied JPEG or MJPEG media with CBS-based bitstream filters","fix":"- Patch: linked from the NVD record (github.com); the fixed version is unknown from the sources","status":"open","published_at":"2026-11-09T19:17:03+00:00","first_seen_at":"2026-11-09T19:28:21+00:00","triaged_at":"2026-11-09T19:31:56+00:00","updated_at":"2026-11-09T19:31:56+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-09T19:31:56Z","model":"claude-haiku-5-5","output":{"fix":"- Patch: linked from the NVD record (github.com); the fixed version is unknown from the sources","reach":"unknown","title":"FFmpeg: crafted JPEG stream crashes the process via miscounted stuffing bytes","impact":"low","summary":"FFmpeg through 9.0.2 miscounts 0xff stuffing bytes in JPEG scan headers in cbs_jpeg_assemble_fragment(). A crafted JPEG or MJPEG stream triggers an av_assert0 abort, so an attacker can crash any process that processes the file.","audience":"businesses","category":"package","nicknames":[],"who_cares":["ffmpeg","media-processing","self-hosted"],"confidence":0.6,"fix_status":"unknown","needs_auth":"no","worst_case":"Denial of service: the FFmpeg process aborts on a crafted file","analyst_note":"Confirm the fixed FFmpeg version from the github.com patch link and the affected CBS bitstream filter paths.","how_to_check":"- Check the installed FFmpeg version with `ffmpeg -version`\n- Look for FFmpeg in services that decode or transcode user-supplied JPEG or MJPEG media with CBS-based bitstream filters","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-untrusted-media","not-using-cbs-filters"],"who_is_affected":"Systems that run FFmpeg on untrusted JPEG or MJPEG input through CBS-based bitstream filters can crash. Batch tools that only process files you produce yourself are unlikely to be exposed. unknown for exact configuration details.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000772,"input_tokens":4635,"output_tokens":618,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-125246':14A,17A '-2026':13A,16A '0xff':30B,80C,95C '9.0.2':28B,66C 'abort':52B,104C 'assembl':40B,76C 'assert0':51B,103C 'attack':55B,87C 'av':50B,102C 'base':108C 'bitstream':109C 'byte':11A,32B,82C 'cbs':38B,74C,107C 'cbs-base':106C 'contain':67C 'craft':2A,43B,91C 'crash':5A,57B 'cve':12A,15A 'denial':69C 'ffmpeg':1A,18B,26B,64C 'file':63B 'filter':110C 'fragment':41B,77C 'header':36B,86C,99C 'host':25B 'jpeg':3A,34B,39B,44B,75C,84C 'jpeg/mjpeg':92C 'media':20B 'media-process':19B 'miscount':9A,29B,79C 'mjpeg':46B 'packag':22B 'process':7A,21B,59B,61B,111C 'scan':35B,85C,98C 'self':24B 'self-host':23B 'servic':71C 'stream':4A,47B,93C 'stuf':10A,31B,81C 'suppli':89C 'trigger':48B,100C 'via':8A 'vulner':72C","nicknames":[],"mitigations":[],"who_affected":"Systems that run FFmpeg on untrusted JPEG or MJPEG input through CBS-based bitstream filters can crash. Batch tools that only process files you produce yourself are unlikely to be exposed. unknown for exact configuration details.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"unknown","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["ffmpeg","mediaprocessing","medium","package","selfhosted"],"campaign_type":null,"search_a":"'-125246':14A,17A '-2026':13A,16A 'byte':11A 'craft':2A 'crash':5A 'cve':12A,15A 'ffmpeg':1A 'jpeg':3A 'miscount':9A 'process':7A 'stream':4A 'stuf':10A 'via':8A","search_b":"'0xff':30B '9.0.2':28B 'abort':52B 'assembl':40B 'assert0':51B 'attack':55B 'av':50B 'byte':32B 'cbs':38B 'craft':43B 'crash':57B 'ffmpeg':18B,26B 'file':63B 'fragment':41B 'header':36B 'host':25B 'jpeg':34B,39B,44B 'media':20B 'media-process':19B 'miscount':29B 'mjpeg':46B 'packag':22B 'process':21B,59B,61B 'scan':35B 'self':24B 'self-host':23B 'stream':47B 'stuf':31B 'trigger':48B","search_c":"'0xff':80C,95C '9.0.2':66C 'abort':104C 'assembl':76C 'assert0':103C 'attack':87C 'av':102C 'base':108C 'bitstream':109C 'byte':82C 'cbs':74C,107C 'cbs-base':106C 'contain':67C 'craft':91C 'denial':69C 'ffmpeg':64C 'filter':110C 'fragment':77C 'header':86C,99C 'jpeg':75C,84C 'jpeg/mjpeg':92C 'miscount':79C 'process':111C 'scan':85C,98C 'servic':71C 'stream':93C 'stuf':81C 'suppli':89C 'trigger':100C 'vulner':72C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-09T19:17:03+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:H/AT:P/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-2026-125246","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-125246","severity":null,"published_at":"2026-11-09T19:17:03+00:00","modified_at":"2026-11-09T19:17:03+00:00","first_seen_at":"2026-11-09T19:28:21+00:00","fetched_at":"2026-11-09T19:28:21+00:00","note":null}],"documents":[{"id":109382,"url":"https://github.com/FFmpeg/FFmpeg/commit/ee457fdcdb3a069ef35910a2e1cacff10906b131","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":109383,"url":"https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-assertion-failure-dos-via-cbs-jpeg-assemble-fragment","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"}