{"id":"CVE-2026-121170","kind":"vulnerability","aliases":["CVE-2026-121170"],"related":[],"title":"Chrome: WebCodecs flaw lets a crafted web page bypass origin policy","description":"Improper resource control in WebCodecs in Google Chrome prior to 157.0.8103.38 allowed a remote attacker to bypass web origin policy via a crafted HTML page. (Chromium security severity: Medium)","summary":"Improper resource control in the WebCodecs API in Google Chrome before 157.0.8103.38 lets a remote attacker bypass the web origin policy using a crafted HTML page. Chromium rates it Medium severity.","severity":"medium","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browsers","chrome","desktop","package"],"not_affected_if":["chrome-157-or-later"],"how_to_check":"- Check the installed Chrome version at chrome://settings/help or with `google-chrome --version` on Linux.\n- Compare it against the fixed version `157.0.8103.38`.","fix":"- Google Chrome: move to `157.0.8103.38` or later.","status":"open","published_at":"2026-11-03T21:17:25+00:00","first_seen_at":"2026-11-03T21:19:24+00:00","triaged_at":"2026-11-03T21:23:19+00:00","updated_at":"2026-11-03T21:23:19+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-03T21:23:19Z","model":"claude-haiku-5-5","output":{"fix":"- Google Chrome: move to `157.0.8103.38` or later.","reach":"internet","title":"Chrome: WebCodecs flaw lets a crafted web page bypass origin policy","impact":"medium","summary":"Improper resource control in the WebCodecs API in Google Chrome before 157.0.8103.38 lets a remote attacker bypass the web origin policy using a crafted HTML page. Chromium rates it Medium severity.","audience":"everyone","category":"package","nicknames":[],"who_cares":["chrome","browsers","desktop"],"confidence":0.6,"fix_status":"available","needs_auth":"no","worst_case":"A crafted web page bypasses origin policy and reads cross-site data.","analyst_note":"","how_to_check":"- Check the installed Chrome version at chrome://settings/help or with `google-chrome --version` on Linux.\n- Compare it against the fixed version `157.0.8103.38`.","plain_action":"Update Google Chrome to version 157.0.8103.38 or later through its built-in update check.","needs_analyst":false,"not_affected_if":["chrome-157-or-later"],"who_is_affected":"Any Chrome install before 157.0.8103.38 is exposed when a user opens a crafted HTML page. Managed or enterprise Chrome fleets should be checked against the same version threshold. Chromium-based browsers that have not yet taken the fix are also a concern, but the sources do not say which ones.","user_interaction":"yes","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000681,"input_tokens":4101,"output_tokens":541,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-121170':14A,17A '-2026':13A,16A '157.0.8103.38':33B,63C 'allow':64C 'api':28B 'attack':37B,67C 'browser':18B 'bypass':9A,38B,69C 'chrome':1A,19B,31B,60C 'chromium':48B,78C 'control':24B,55C 'craft':6A,45B,75C 'cve':12A,15A 'desktop':20B 'flaw':3A 'googl':30B,59C 'html':46B,76C 'improp':22B,53C 'let':4A,34B 'medium':51B,81C 'origin':10A,41B,71C 'packag':21B 'page':8A,47B,77C 'polici':11A,42B,72C 'prior':61C 'rate':49B 'remot':36B,66C 'resourc':23B,54C 'secur':79C 'sever':52B,80C 'use':43B 'via':73C 'web':7A,40B,70C 'webcodec':2A,27B,57C","nicknames":[],"mitigations":[],"who_affected":"Any Chrome install before 157.0.8103.38 is exposed when a user opens a crafted HTML page. Managed or enterprise Chrome fleets should be checked against the same version threshold. Chromium-based browsers that have not yet taken the fix are also a concern, but the sources do not say which ones.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"everyone","plain_action":"Update Google Chrome to version 157.0.8103.38 or later through its built-in update check.","pkeys":[],"ptokens":[],"labels":["browsers","chrome","desktop","medium","package"],"campaign_type":null,"first_public_at":"2026-11-03T21:17:25+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-121170","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121170","severity":null,"published_at":"2026-11-03T21:17:25+00:00","modified_at":"2026-11-03T21:17:25+00:00","first_seen_at":"2026-11-03T21:19:24+00:00","fetched_at":"2026-11-03T21:19:24+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"}