{"id":"CVE-2026-121129","kind":"vulnerability","aliases":["CVE-2026-121129"],"related":[],"title":"Chrome: WebRTC use-after-free lets a crafted web page run code","description":"Use after free in WebRTC in Google Chrome prior to 157.0.8103.38 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: High)","summary":"A use-after-free bug in the WebRTC component of Google Chrome before 157.0.8103.38 can be triggered by a crafted HTML page. A remote attacker can execute arbitrary code inside the browser sandbox.","severity":"high","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browsers","chrome","endpoints","runtime"],"not_affected_if":["chrome-up-to-date"],"how_to_check":"- Open Chrome's About page (chrome://settings/help) and read the installed version\n- Check whether the version is below `157.0.8103.38`","fix":"- Google Chrome: move to `157.0.8103.38` or later","status":"open","published_at":"2026-11-03T21:17:21+00:00","first_seen_at":"2026-11-03T21:19:20+00:00","triaged_at":"2026-11-03T21:24:51+00:00","updated_at":"2026-11-03T21:24:51+00:00","category":"runtime","confidence":0.7,"triage":{"at":"2026-11-03T21:24:51Z","model":"claude-haiku-5-5","output":{"fix":"- Google Chrome: move to `157.0.8103.38` or later","reach":"internet","title":"Chrome: WebRTC use-after-free lets a crafted web page run code","impact":"high","summary":"A use-after-free bug in the WebRTC component of Google Chrome before 157.0.8103.38 can be triggered by a crafted HTML page. A remote attacker can execute arbitrary code inside the browser sandbox.","audience":"everyone","category":"runtime","nicknames":[],"who_cares":["chrome","browsers","endpoints"],"confidence":0.7,"fix_status":"available","needs_auth":"no","worst_case":"Attacker runs code inside the browser sandbox after a user visits a page","analyst_note":"","how_to_check":"- Open Chrome's About page (chrome://settings/help) and read the installed version\n- Check whether the version is below `157.0.8103.38`","plain_action":"Update Google Chrome to version 157.0.8103.38 or later: Chrome menu > Help > About Google Chrome.","needs_analyst":false,"not_affected_if":["chrome-up-to-date"],"who_is_affected":"Anyone running Google Chrome older than 157.0.8103.38 who visits a page an attacker controls. The sources do not say whether WebRTC must be in active use, so the exposure is any browsing session. Managed fleets should confirm the version across endpoints.","user_interaction":"yes","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000671,"input_tokens":4105,"output_tokens":521,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-121129':16A,19A '-2026':15A,18A '157.0.8103.38':38B,68C 'allow':69C 'arbitrari':52B,75C 'attack':49B,72C 'browser':20B,56B 'bug':29B 'chrome':1A,21B,36B,65C 'chromium':85C 'code':13A,53B,76C 'compon':33B 'craft':9A,44B,82C 'cve':14A,17A 'endpoint':22B 'execut':51B,74C 'free':6A,28B,60C 'googl':35B,64C 'high':88C 'html':45B,83C 'insid':54B,77C 'let':7A 'page':11A,46B,84C 'prior':66C 'remot':48B,71C 'run':12A 'runtim':23B 'sandbox':57B,79C 'secur':86C 'sever':87C 'trigger':41B 'use':4A,26B,58C 'use-after-fre':3A,25B 'via':80C 'web':10A 'webrtc':2A,32B,62C","nicknames":[],"mitigations":[],"who_affected":"Anyone running Google Chrome older than 157.0.8103.38 who visits a page an attacker controls. The sources do not say whether WebRTC must be in active use, so the exposure is any browsing session. Managed fleets should confirm the version across endpoints.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"everyone","plain_action":"Update Google Chrome to version 157.0.8103.38 or later: Chrome menu > Help > About Google Chrome.","pkeys":[],"ptokens":[],"labels":["browsers","chrome","endpoints","high","runtime"],"campaign_type":null,"first_public_at":"2026-11-03T21:17:21+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-121129","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121129","severity":null,"published_at":"2026-11-03T21:17:21+00:00","modified_at":"2026-11-03T21:17:21+00:00","first_seen_at":"2026-11-03T21:19:20+00:00","fetched_at":"2026-11-03T21:19:20+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}