{"id":"CVE-2026-128240","kind":"vulnerability","aliases":["CVE-2026-128240"],"related":[],"title":"GPAC: crafted scene file triggers use-after-free and crashes MP4Box","description":"GPAC through 26.07.0 contains a use-after-free vulnerability in gf_sg_proto_del() in src/scenegraph/vrml_proto.c because gf_sg_reset() frees unregistered prototypes still referenced by scene commands. Attackers can supply a crafted XMT/BT scene declaring prototypes via commands, processed by MP4Box -chap, to trigger freed memory access and crash the process.","summary":"GPAC through 26.07.0 frees unregistered prototypes in gf_sg_reset() while scene commands still reference them. A crafted XMT/BT scene file processed by MP4Box -chap can make the process access freed memory and crash.","severity":"medium","cvss":6.8,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"GPAC","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["gpac","media-processing","mp4box","package"],"not_affected_if":["gpac-not-installed","no-untrusted-input"],"how_to_check":"- Run `MP4Box -version` to see the installed GPAC version and compare it with the fixed release.\n- Check whether anything runs `MP4Box -chap` on untrusted XMT or BT files.","fix":null,"status":"open","published_at":"2026-11-13T10:18:11+00:00","first_seen_at":"2026-11-13T10:47:33+00:00","triaged_at":"2026-11-13T10:54:55+00:00","updated_at":"2026-11-13T10:54:55+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-13T10:54:55Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"GPAC: crafted scene file triggers use-after-free and crashes MP4Box","impact":"low","summary":"GPAC through 26.07.0 frees unregistered prototypes in gf_sg_reset() while scene commands still reference them. A crafted XMT/BT scene file processed by MP4Box -chap can make the process access freed memory and crash.","audience":"developers","category":"package","nicknames":[],"who_cares":["gpac","mp4box","media-processing"],"confidence":0.6,"fix_status":"unknown","needs_auth":"no","worst_case":"Process crashes after reading freed memory from a crafted scene file","analyst_note":"Confirm the fixed GPAC version and whether the linked GitHub patch is the official fix; the sources do not state a fixed version.","how_to_check":"- Run `MP4Box -version` to see the installed GPAC version and compare it with the fixed release.\n- Check whether anything runs `MP4Box -chap` on untrusted XMT or BT files.","plain_action":"","product_name":"GPAC","needs_analyst":true,"not_affected_if":["no-untrusted-input","gpac-not-installed"],"who_is_affected":"Systems that run GPAC's MP4Box tool with `-chap` on XMT or BT scene files from untrusted sources can be hit. The sources describe a crash rather than code execution. Teams that only process their own media files or do not use GPAC can skip it.","user_interaction":"unknown","product_ecosystem":"vendor","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000745,"input_tokens":4646,"output_tokens":560,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-128240':15A,18A '-2026':14A,17A '26.07.0':28B,62C 'access':55B,108C 'attack':89C 'chap':50B,103C 'command':38B,88C,99C 'contain':63C 'craft':2A,43B,93C 'crash':11A,59B,110C 'cve':13A,16A 'declar':96C 'del':74C 'file':4A,46B 'free':9A,29B,68C,81C 'freed':56B,106C 'gf':33B,71C,78C 'gpac':1A,19A,20B,26B,60C 'make':52B 'media':22B 'media-process':21B 'memori':57B,107C 'mp4box':12A,24B,49B,102C 'packag':25B 'process':23B,47B,54B,100C,112C 'proto':73C 'prototyp':31B,83C,97C 'refer':40B 'referenc':85C 'reset':35B,80C 'scene':3A,37B,45B,87C,95C 'sg':34B,72C,79C 'src/scenegraph/vrml_proto.c':76C 'still':39B,84C 'suppli':91C 'trigger':5A,105C 'unregist':30B,82C 'use':7A,66C 'use-after-fre':6A,65C 'via':98C 'vulner':69C 'xmt/bt':44B,94C","nicknames":[],"mitigations":[],"who_affected":"Systems that run GPAC's MP4Box tool with `-chap` on XMT or BT scene files from untrusted sources can be hit. The sources describe a crash rather than code execution. Teams that only process their own media files or do not use GPAC can skip it.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"developers","plain_action":null,"pkeys":["gpac"],"ptokens":["gpac"],"labels":["gpac","mediaprocessing","medium","mp4box","package","vendor"],"campaign_type":null,"search_a":"'-128240':15A,18A '-2026':14A,17A 'craft':2A 'crash':11A 'cve':13A,16A 'file':4A 'free':9A 'gpac':1A,19A 'mp4box':12A 'scene':3A 'trigger':5A 'use':7A 'use-after-fre':6A","search_b":"'26.07.0':28B 'access':55B 'chap':50B 'command':38B 'craft':43B 'crash':59B 'file':46B 'free':29B 'freed':56B 'gf':33B 'gpac':20B,26B 'make':52B 'media':22B 'media-process':21B 'memori':57B 'mp4box':24B,49B 'packag':25B 'process':23B,47B,54B 'prototyp':31B 'refer':40B 'reset':35B 'scene':37B,45B 'sg':34B 'still':39B 'unregist':30B 'xmt/bt':44B","search_c":"'26.07.0':62C 'access':108C 'attack':89C 'chap':103C 'command':88C,99C 'contain':63C 'craft':93C 'crash':110C 'declar':96C 'del':74C 'free':68C,81C 'freed':106C 'gf':71C,78C 'gpac':60C 'memori':107C 'mp4box':102C 'process':100C,112C 'proto':73C 'prototyp':83C,97C 'referenc':85C 'reset':80C 'scene':87C,95C 'sg':72C,79C 'src/scenegraph/vrml_proto.c':76C 'still':84C 'suppli':91C 'trigger':105C 'unregist':82C 'use':66C 'use-after-fre':65C 'via':98C 'vulner':69C 'xmt/bt':94C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-13T10:18:11+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-2026-128240","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-128240","severity":null,"published_at":"2026-11-13T10:18:11+00:00","modified_at":"2026-11-13T10:18:11+00:00","first_seen_at":"2026-11-13T10:47:33+00:00","fetched_at":"2026-11-13T10:47:33+00:00","note":null}],"documents":[{"id":145430,"url":"https://github.com/gpac/gpac/commit/a2e5c62c213b5329a4572fe8e7c333e1ca26d028","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":145431,"url":"https://www.vulncheck.com/advisories/gpac-through-26.07.0-use-after-free-in-gf-sg-proto-del-during-scene-teardown","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"}