{"id":"CVE-2026-121103","kind":"vulnerability","aliases":["CVE-2026-121103"],"related":[],"title":"Chrome: extension authorization flaw lets a site read cross-origin data","description":"Incorrect authorization in Extensions in Google Chrome prior to 157.0.8103.38 allowed a remote attacker to obtain cross-origin data via a crafted Chrome extension. (Chromium security severity: Medium)","summary":"Google Chrome versions before 157.0.8103.38 have an incorrect authorization bug in extensions. A remote attacker can use a crafted Chrome extension to obtain data from other origins.","severity":"medium","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browser","chrome","desktop","package"],"not_affected_if":["chrome-157-or-later"],"how_to_check":"- Check the installed Chrome version at chrome://settings/help and compare it with `157.0.8103.38`\n- Review which extensions are installed at chrome://extensions","fix":"- Google Chrome: move to `157.0.8103.38` or later","status":"open","published_at":"2026-11-03T21:17:16+00:00","first_seen_at":"2026-11-03T21:19:14+00:00","triaged_at":"2026-11-03T21:25:16+00:00","updated_at":"2026-11-03T21:25:16+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-03T21:25:16Z","model":"claude-haiku-5-5","output":{"fix":"- Google Chrome: move to `157.0.8103.38` or later","reach":"internet","title":"Chrome: extension authorization flaw lets a site read cross-origin data","impact":"medium","summary":"Google Chrome versions before 157.0.8103.38 have an incorrect authorization bug in extensions. A remote attacker can use a crafted Chrome extension to obtain data from other origins.","audience":"everyone","category":"package","nicknames":[],"who_cares":["chrome","browser","desktop"],"confidence":0.6,"fix_status":"available","needs_auth":"no","worst_case":"Attacker reads cross-origin data from sites the user visits","analyst_note":"","how_to_check":"- Check the installed Chrome version at chrome://settings/help and compare it with `157.0.8103.38`\n- Review which extensions are installed at chrome://extensions","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-157-or-later"],"who_is_affected":"Any desktop Chrome install older than 157.0.8103.38 is exposed, since the flaw lives in the browser's extension handling. Exposure depends on a malicious extension or page reaching the data, so users who keep extensions to a trusted set are at lower risk. Managed fleets should confirm the Chrome version across machines.","user_interaction":"yes","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000677,"input_tokens":4104,"output_tokens":533,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-121103':15A,18A '-2026':14A,17A '157.0.8103.38':27B,59C 'allow':60C 'attack':37B,63C 'author':3A,31B,51C 'browser':19B 'bug':32B 'chrome':1A,20B,24B,42B,56C,73C 'chromium':75C 'craft':41B,72C 'cross':10A,67C 'cross-origin':9A,66C 'cve':13A,16A 'data':12A,46B,69C 'desktop':21B 'extens':2A,34B,43B,53C,74C 'flaw':4A 'googl':23B,55C 'incorrect':30B,50C 'let':5A 'medium':78C 'obtain':45B,65C 'origin':11A,49B,68C 'packag':22B 'prior':57C 'read':8A 'remot':36B,62C 'secur':76C 'sever':77C 'site':7A 'use':39B 'version':25B 'via':70C","nicknames":[],"mitigations":[],"who_affected":"Any desktop Chrome install older than 157.0.8103.38 is exposed, since the flaw lives in the browser's extension handling. Exposure depends on a malicious extension or page reaching the data, so users who keep extensions to a trusted set are at lower risk. Managed fleets should confirm the Chrome version across machines.","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","desktop","medium","package"],"campaign_type":null,"first_public_at":"2026-11-03T21:17:16+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-121103","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121103","severity":null,"published_at":"2026-11-03T21:17:16+00:00","modified_at":"2026-11-03T21:17:16+00:00","first_seen_at":"2026-11-03T21:19:14+00:00","fetched_at":"2026-11-03T21:19:14+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"}