{"id":"CVE-2026-125173","kind":"vulnerability","aliases":["CVE-2026-125173"],"related":[],"title":"FFmpeg: crafted EVC stream leaks memory in libxevd decoder","description":"FFmpeg through 9.0.2 contains a memory leak vulnerability in libxevd_receive_frame() in libavcodec/libxevd.c that fails to free pkt_au when an access unit produces no picture. Attackers can supply a crafted EVC stream with many access units containing only parameter sets or non-frame NAL units to exhaust memory in the decoding application.","summary":"FFmpeg's libxevd decoder fails to free a packet buffer when an access unit contains no picture. A crafted EVC stream with many such access units exhausts memory in the application that decodes it.","severity":"medium","cvss":6.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["ffmpeg","runtime","self-hosted","video-processing"],"not_affected_if":["no-evc-decoding","untrusted-input-absent"],"how_to_check":"- Check the installed FFmpeg version with `ffmpeg -version` and compare it with the fixed release listed in the sources.\n- Check whether the build includes the libxevd EVC decoder (`ffmpeg -decoders | grep -i xevd`).","fix":"- Fixed version: unknown, the sources do not name it.\n- Patch referenced in sources: github.com (link only, content not read).","status":"open","published_at":"2026-11-09T19:16:52+00:00","first_seen_at":"2026-11-09T19:28:16+00:00","triaged_at":"2026-11-09T19:31:38+00:00","updated_at":"2026-11-09T19:31:38+00:00","category":"runtime","confidence":0.6,"triage":{"at":"2026-11-09T19:31:38Z","model":"claude-haiku-5-5","output":{"fix":"- Fixed version: unknown, the sources do not name it.\n- Patch referenced in sources: github.com (link only, content not read).","reach":"network","title":"FFmpeg: crafted EVC stream leaks memory in libxevd decoder","impact":"low","summary":"FFmpeg's libxevd decoder fails to free a packet buffer when an access unit contains no picture. A crafted EVC stream with many such access units exhausts memory in the application that decodes it.","audience":"businesses","category":"runtime","nicknames":[],"who_cares":["ffmpeg","video-processing","self-hosted"],"confidence":0.6,"fix_status":"available","needs_auth":"no","worst_case":"Attacker exhausts memory, crashing the decoding application","analyst_note":"Confirm the first fixed FFmpeg version and whether libxevd is enabled by default, using the patch link and NVD entry.","how_to_check":"- Check the installed FFmpeg version with `ffmpeg -version` and compare it with the fixed release listed in the sources.\n- Check whether the build includes the libxevd EVC decoder (`ffmpeg -decoders | grep -i xevd`).\n- unknown for anything beyond this, the sources do not say.","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-evc-decoding","untrusted-input-absent"],"who_is_affected":"Applications that decode EVC (MPEG-5) video with FFmpeg's libxevd decoder are exposed, and an attacker needs to supply the stream to them. Systems that never decode untrusted EVC input can skip it. unknown whether a default build enables libxevd.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"yes","severity_if_unknown":"unknown"},"cost_usd":0.000767,"input_tokens":4626,"output_tokens":609,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-125173':12A,15A '-2026':11A,14A '9.0.2':59C 'access':36B,48B,79C,93C 'applic':54B,111C 'attack':84C 'au':76C 'buffer':33B 'contain':38B,60C,95C 'craft':2A,42B,88C 'cve':10A,13A 'decod':9A,27B,56B,110C 'evc':3A,43B,89C 'exhaust':50B,106C 'fail':28B,72C 'ffmpeg':1A,16B,24B,57C 'frame':68C,102C 'free':30B,74C 'host':20B 'leak':5A,63C 'libavcodec/libxevd.c':70C 'libxevd':8A,26B,66C 'mani':46B,92C 'memori':6A,51B,62C,107C 'nal':103C 'non':101C 'non-fram':100C 'packet':32B 'paramet':97C 'pictur':40B,83C 'pkt':75C 'process':23B 'produc':81C 'receiv':67C 'runtim':17B 'self':19B 'self-host':18B 'set':98C 'stream':4A,44B,90C 'suppli':86C 'unit':37B,49B,80C,94C,104C 'video':22B 'video-process':21B 'vulner':64C","nicknames":[],"mitigations":[],"who_affected":"Applications that decode EVC (MPEG-5) video with FFmpeg's libxevd decoder are exposed, and an attacker needs to supply the stream to them. Systems that never decode untrusted EVC input can skip it. unknown whether a default build enables libxevd.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["ffmpeg","medium","runtime","selfhosted","videoprocessing"],"campaign_type":null,"search_a":"'-125173':12A,15A '-2026':11A,14A 'craft':2A 'cve':10A,13A 'decod':9A 'evc':3A 'ffmpeg':1A 'leak':5A 'libxevd':8A 'memori':6A 'stream':4A","search_b":"'access':36B,48B 'applic':54B 'buffer':33B 'contain':38B 'craft':42B 'decod':27B,56B 'evc':43B 'exhaust':50B 'fail':28B 'ffmpeg':16B,24B 'free':30B 'host':20B 'libxevd':26B 'mani':46B 'memori':51B 'packet':32B 'pictur':40B 'process':23B 'runtim':17B 'self':19B 'self-host':18B 'stream':44B 'unit':37B,49B 'video':22B 'video-process':21B","search_c":"'9.0.2':59C 'access':79C,93C 'applic':111C 'attack':84C 'au':76C 'contain':60C,95C 'craft':88C 'decod':110C 'evc':89C 'exhaust':106C 'fail':72C 'ffmpeg':57C 'frame':68C,102C 'free':74C 'leak':63C 'libavcodec/libxevd.c':70C 'libxevd':66C 'mani':92C 'memori':62C,107C 'nal':103C 'non':101C 'non-fram':100C 'paramet':97C 'pictur':83C 'pkt':75C 'produc':81C 'receiv':67C 'set':98C 'stream':90C 'suppli':86C 'unit':80C,94C,104C 'vulner':64C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-09T19:16:52+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-2026-125173","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-125173","severity":null,"published_at":"2026-11-09T19:16:52+00:00","modified_at":"2026-11-09T19:16:52+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":109233,"url":"https://github.com/FFmpeg/FFmpeg/commit/250303c2a59a71bfc544a6b583bc17b6cf0ca903","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":109234,"url":"https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-memory-leak-in-libxevd-evc-decoder-wrapper","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"}