{"id":"CVE-2026-121223","kind":"vulnerability","aliases":["CVE-2026-121223"],"related":[],"title":"Chrome: media timing discrepancy lets a web page leak cross-origin data","description":"Observable discrepancy in Media in Google Chrome prior to 157.0.8103.38 allowed a remote attacker to leak cross-origin data via a crafted HTML page. (Chromium security severity: Medium)","summary":"A flaw in the Media component of Google Chrome before 157.0.8103.38 lets a remote attacker build a crafted HTML page that reveals data from other origins. The Chromium security severity is rated Medium.","severity":"medium","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browser","chrome","desktop","runtime"],"not_affected_if":["chrome-up-to-date"],"how_to_check":"- Check the installed Chrome version at chrome://settings/help and compare it to `157.0.8103.38`.","fix":"- Google Chrome: move to `157.0.8103.38` or later.","status":"open","published_at":"2026-11-03T21:17:32+00:00","first_seen_at":"2026-11-03T21:19:27+00:00","triaged_at":"2026-11-03T21:21:27+00:00","updated_at":"2026-11-03T21:21:27+00:00","category":"runtime","confidence":0.6,"triage":{"at":"2026-11-03T21:21:27Z","model":"claude-haiku-5-5","output":{"fix":"- Google Chrome: move to `157.0.8103.38` or later.","reach":"internet","title":"Chrome: media timing discrepancy lets a web page leak cross-origin data","impact":"medium","summary":"A flaw in the Media component of Google Chrome before 157.0.8103.38 lets a remote attacker build a crafted HTML page that reveals data from other origins. The Chromium security severity is rated Medium.","audience":"everyone","category":"runtime","nicknames":[],"who_cares":["chrome","browser","desktop"],"confidence":0.6,"fix_status":"available","needs_auth":"no","worst_case":"cross-origin data from other sites is readable by the attacker","analyst_note":"","how_to_check":"- Check the installed Chrome version at chrome://settings/help and compare it to `157.0.8103.38`.\n- unknown for other checks; the sources do not say.","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-up-to-date"],"who_is_affected":"Anyone running Google Chrome older than 157.0.8103.38 who opens a malicious web page. Browsers on the same machine with other engines are not covered by this entry. Managed fleets that pin Chrome versions are exposed until the pin moves.","user_interaction":"yes","needs_special_setup":"no","severity_if_unknown":"medium"},"cost_usd":0.000662,"input_tokens":4096,"output_tokens":504,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-121223':16A,19A '-2026':15A,18A '157.0.8103.38':34B,66C 'allow':67C 'attack':38B,70C 'browser':20B 'build':39B 'chrome':1A,21B,32B,63C 'chromium':51B,82C 'compon':29B 'craft':41B,79C 'cross':11A,74C 'cross-origin':10A,73C 'cve':14A,17A 'data':13A,46B,76C 'desktop':22B 'discrep':4A,58C 'flaw':25B 'googl':31B,62C 'html':42B,80C 'leak':9A,72C 'let':5A,35B 'media':2A,28B,60C 'medium':56B,85C 'observ':57C 'origin':12A,49B,75C 'page':8A,43B,81C 'prior':64C 'rate':55B 'remot':37B,69C 'reveal':45B 'runtim':23B 'secur':52B,83C 'sever':53B,84C 'time':3A 'via':77C 'web':7A","nicknames":[],"mitigations":[],"who_affected":"Anyone running Google Chrome older than 157.0.8103.38 who opens a malicious web page. Browsers on the same machine with other engines are not covered by this entry. Managed fleets that pin Chrome versions are exposed until the pin moves.","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":["browser","chrome","desktop","medium","runtime"],"campaign_type":null,"first_public_at":"2026-11-03T21:17:32+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-121223","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121223","severity":null,"published_at":"2026-11-03T21:17:32+00:00","modified_at":"2026-11-03T21:17:32+00:00","first_seen_at":"2026-11-03T21:19:27+00:00","fetched_at":"2026-11-03T21:19:27+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"}