{"id":"CVE-2026-125240","kind":"vulnerability","aliases":["CVE-2026-125240"],"related":[],"title":"FFmpeg: crafted JPEG XS stream leaks decoder memory until the process exhausts memory","description":"FFmpeg through 9.0.2 contains a resource leak vulnerability in svt_jpegxs_dec_decode() in libsvtjpegxsdec.c that leaks decoder instances when ff_set_dimensions() rejects frame dimensions. Attackers can supply a crafted JPEG XS stream, for example in MPEG-TS, with oversized headers to repeatedly leak decoder threads and buffers, exhausting memory.","summary":"FFmpeg through 9.0.2 leaks decoder instances and buffers in its SVT JPEG XS decoder when frame dimensions are rejected. A crafted JPEG XS stream, for example inside MPEG-TS, can repeatedly trigger the leak and exhaust memory.","severity":"medium","cvss":6.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["ffmpeg","media-processing","runtime","self-hosted","transcoding"],"not_affected_if":["no-svt-jpegxs-decoder","no-untrusted-input"],"how_to_check":"- Check the installed FFmpeg version with `ffmpeg -version`; versions through `9.0.2` are in the affected range.\n- Check whether FFmpeg was built with SVT JPEG XS support (libsvtjpegxsdec), for example in the output of `ffmpeg -decoders | grep -i jpegxs`.","fix":null,"status":"open","published_at":"2026-11-09T19:17:02+00:00","first_seen_at":"2026-11-09T19:28:20+00:00","triaged_at":"2026-11-09T19:30:24+00:00","updated_at":"2026-11-09T19:30:24+00:00","category":"runtime","confidence":0.6,"triage":{"at":"2026-11-09T19:30:24Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"internet","title":"FFmpeg: crafted JPEG XS stream leaks decoder memory until the process exhausts memory","impact":"medium","summary":"FFmpeg through 9.0.2 leaks decoder instances and buffers in its SVT JPEG XS decoder when frame dimensions are rejected. A crafted JPEG XS stream, for example inside MPEG-TS, can repeatedly trigger the leak and exhaust memory.","audience":"developers","category":"runtime","nicknames":[],"who_cares":["ffmpeg","media-processing","transcoding","self-hosted"],"confidence":0.6,"fix_status":"unknown","needs_auth":"no","worst_case":"Repeated decoding exhausts server memory, causing denial of service.","analyst_note":"Find the fixed FFmpeg version and the patch commit via the linked GitHub patch and the VulnCheck advisory; the sources here do not state a fix.","how_to_check":"- Check the installed FFmpeg version with `ffmpeg -version`; versions through `9.0.2` are in the affected range.\n- Check whether FFmpeg was built with SVT JPEG XS support (libsvtjpegxsdec), for example in the output of `ffmpeg -decoders | grep -i jpegxs`.","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-untrusted-input","no-svt-jpegxs-decoder"],"who_is_affected":"Systems that run FFmpeg to decode untrusted media, such as transcoding services or media pipelines accepting uploaded or streamed MPEG-TS content, are the exposed ones. Installations that only process trusted local files, or that lack the SVT JPEG XS decoder, are less exposed. The sources do not say which FFmpeg version fixes it.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.000798,"input_tokens":4656,"output_tokens":665,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-125240':16A,19A '-2026':15A,18A '9.0.2':31B,69C 'attack':93C 'buffer':36B,116C 'contain':70C 'craft':2A,49B,97C 'cve':14A,17A 'dec':78C 'decod':7A,33B,42B,79C,84C,113C 'dimens':45B,89C,92C 'exampl':54B,102C 'exhaust':12A,65B,117C 'ff':87C 'ffmpeg':1A,20B,29B,67C 'frame':44B,91C 'header':109C 'host':27B 'insid':55B 'instanc':34B,85C 'jpeg':3A,40B,50B,98C 'jpegx':77C 'leak':6A,32B,63B,73C,83C,112C 'libsvtjpegxsdec.c':81C 'media':22B 'media-process':21B 'memori':8A,13A,66B,118C 'mpeg':57B,105C 'mpeg-t':56B,104C 'overs':108C 'process':11A,23B 'reject':47B,90C 'repeat':60B,111C 'resourc':72C 'runtim':24B 'self':26B 'self-host':25B 'set':88C 'stream':5A,52B,100C 'suppli':95C 'svt':39B,76C 'thread':114C 'transcod':28B 'trigger':61B 'ts':58B,106C 'vulner':74C 'xs':4A,41B,51B,99C","nicknames":[],"mitigations":[],"who_affected":"Systems that run FFmpeg to decode untrusted media, such as transcoding services or media pipelines accepting uploaded or streamed MPEG-TS content, are the exposed ones. Installations that only process trusted local files, or that lack the SVT JPEG XS decoder, are less exposed. The sources do not say which FFmpeg version fixes it.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["ffmpeg","mediaprocessing","medium","runtime","selfhosted","transcoding"],"campaign_type":null,"search_a":"'-125240':16A,19A '-2026':15A,18A 'craft':2A 'cve':14A,17A 'decod':7A 'exhaust':12A 'ffmpeg':1A 'jpeg':3A 'leak':6A 'memori':8A,13A 'process':11A 'stream':5A 'xs':4A","search_b":"'9.0.2':31B 'buffer':36B 'craft':49B 'decod':33B,42B 'dimens':45B 'exampl':54B 'exhaust':65B 'ffmpeg':20B,29B 'frame':44B 'host':27B 'insid':55B 'instanc':34B 'jpeg':40B,50B 'leak':32B,63B 'media':22B 'media-process':21B 'memori':66B 'mpeg':57B 'mpeg-t':56B 'process':23B 'reject':47B 'repeat':60B 'runtim':24B 'self':26B 'self-host':25B 'stream':52B 'svt':39B 'transcod':28B 'trigger':61B 'ts':58B 'xs':41B,51B","search_c":"'9.0.2':69C 'attack':93C 'buffer':116C 'contain':70C 'craft':97C 'dec':78C 'decod':79C,84C,113C 'dimens':89C,92C 'exampl':102C 'exhaust':117C 'ff':87C 'ffmpeg':67C 'frame':91C 'header':109C 'instanc':85C 'jpeg':98C 'jpegx':77C 'leak':73C,83C,112C 'libsvtjpegxsdec.c':81C 'memori':118C 'mpeg':105C 'mpeg-t':104C 'overs':108C 'reject':90C 'repeat':111C 'resourc':72C 'set':88C 'stream':100C 'suppli':95C 'svt':76C 'thread':114C 'ts':106C 'vulner':74C 'xs':99C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-09T19:17:02+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-2026-125240","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-125240","severity":null,"published_at":"2026-11-09T19:17:02+00:00","modified_at":"2026-11-09T19:17:02+00:00","first_seen_at":"2026-11-09T19:28:20+00:00","fetched_at":"2026-11-09T19:28:20+00:00","note":null}],"documents":[{"id":109369,"url":"https://github.com/FFmpeg/FFmpeg/commit/3aa561b0dd2054182fbb9548b4526e8500d52a52","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":109370,"url":"https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-resource-leak-in-libsvtjpegxs-jpeg-xs-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"}