{"id":"CVE-2026-121251","kind":"vulnerability","aliases":["CVE-2026-121251"],"related":[],"title":"Chrome: V8 authorization gap lets a crafted page bypass web origin policy","description":"Missing authorization in V8 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: Low)","summary":"A missing authorization check in the V8 JavaScript engine in Google Chrome versions before 157.0.8103.38 lets a remote attacker bypass web origin policy using a crafted HTML page. Chromium rates it Low severity, and the source does not say what data an attacker could read or change.","severity":"low","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browser","chrome","runtime","web-users"],"not_affected_if":["chrome-up-to-date"],"how_to_check":"- Check the installed Chrome version at chrome://settings/help and compare it with `157.0.8103.38`.","fix":"- Google Chrome: move to `157.0.8103.38` or later.","status":"open","published_at":"2026-11-03T21:17:35+00:00","first_seen_at":"2026-11-03T21:19:29+00:00","triaged_at":"2026-11-03T21:20:58+00:00","updated_at":"2026-11-03T21:20:58+00:00","category":"runtime","confidence":0.6,"triage":{"at":"2026-11-03T21:20:58Z","model":"claude-haiku-5-5","output":{"fix":"- Google Chrome: move to `157.0.8103.38` or later.","reach":"internet","title":"Chrome: V8 authorization gap lets a crafted page bypass web origin policy","impact":"medium","summary":"A missing authorization check in the V8 JavaScript engine in Google Chrome versions before 157.0.8103.38 lets a remote attacker bypass web origin policy using a crafted HTML page. Chromium rates it Low severity, and the source does not say what data an attacker could read or change.","audience":"everyone","category":"runtime","nicknames":[],"who_cares":["chrome","browser","web-users"],"confidence":0.6,"fix_status":"available","needs_auth":"no","worst_case":"Malicious page bypasses origin policy, reading cross-site data in the browser","analyst_note":"Confirm the exact impact of the origin policy bypass and whether it is exploited, using the NVD entry and the Chrome release notes for 157.0.8103.38.","how_to_check":"- Check the installed Chrome version at chrome://settings/help and compare it with `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: Chrome menu > Help > About Google Chrome.","needs_analyst":true,"not_affected_if":["chrome-up-to-date"],"who_is_affected":"Anyone browsing with Google Chrome before 157.0.8103.38 is exposed when they open a malicious web page. Managed or enterprise Chrome fleets should be checked for the installed version. unknown for any further detail the sources do not state.","user_interaction":"yes","needs_special_setup":"no","severity_if_unknown":"low"},"cost_usd":0.00071,"input_tokens":4097,"output_tokens":600,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-121251':15A,18A '-2026':14A,17A '157.0.8103.38':39B,81C 'allow':82C 'attack':43B,67B,85C 'author':3A,27B,73C 'browser':19B 'bypass':9A,44B,87C 'chang':71B 'check':28B 'chrome':1A,20B,36B,78C 'chromium':53B,96C 'could':68B 'craft':7A,50B,93C 'cve':13A,16A 'data':65B 'engin':33B 'gap':4A 'googl':35B,77C 'html':51B,94C 'javascript':32B 'let':5A,40B 'low':56B,99C 'miss':26B,72C 'origin':11A,46B,89C 'page':8A,52B,95C 'polici':12A,47B,90C 'prior':79C 'rate':54B 'read':69B 'remot':42B,84C 'runtim':21B 'say':63B 'secur':97C 'sever':57B,98C 'sourc':60B 'use':48B 'user':24B 'v8':2A,31B,75C 'version':37B 'via':91C 'web':10A,23B,45B,88C 'web-us':22B","nicknames":[],"mitigations":[],"who_affected":"Anyone browsing with Google Chrome before 157.0.8103.38 is exposed when they open a malicious web page. Managed or enterprise Chrome fleets should be checked for the installed version. unknown for any further detail the sources do not state.","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: Chrome menu > Help > About Google Chrome.","pkeys":[],"ptokens":[],"labels":["browser","chrome","low","runtime","webusers"],"campaign_type":null,"first_public_at":"2026-11-03T21:17:35+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-121251","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121251","severity":null,"published_at":"2026-11-03T21:17:35+00:00","modified_at":"2026-11-03T21:17:35+00:00","first_seen_at":"2026-11-03T21:19:29+00:00","fetched_at":"2026-11-03T21:19:29+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"}