{"id":"CVE-2026-121063","kind":"vulnerability","aliases":["CVE-2026-121063"],"related":[],"title":"Chrome: CacheStorage authorization flaw lets compromised renderer bypass site isolation","description":"Incorrect authorization in CacheStorage in Google Chrome prior to 157.0.8103.38 allowed a remote attacker who had compromised the renderer process to bypass site isolation via a crafted HTML page. (Chromium security severity: Medium)","summary":"Google Chrome's CacheStorage component has an incorrect authorization check that lets a remote attacker who already controls the renderer process bypass site isolation via 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","other"],"not_affected_if":["chrome-at-or-above-157.0.8103.38"],"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":"2026-11-03T21:17:10+00:00","first_seen_at":"2026-11-03T21:19:11+00:00","triaged_at":"2026-11-03T21:27:04+00:00","updated_at":"2026-11-03T21:27:04+00:00","category":"other","confidence":0.7,"triage":{"at":"2026-11-03T21:27:04Z","model":"claude-haiku-5-5","output":{"fix":"- Google Chrome: move to `157.0.8103.38` or later","reach":"internet","title":"Chrome: CacheStorage authorization flaw lets compromised renderer bypass site isolation","impact":"medium","summary":"Google Chrome's CacheStorage component has an incorrect authorization check that lets a remote attacker who already controls the renderer process bypass site isolation via a crafted HTML page. Chromium rates it Medium severity.","audience":"everyone","category":"other","nicknames":[],"who_cares":["chrome","browsers","desktop"],"confidence":0.7,"fix_status":"available","needs_auth":"no","worst_case":"attacker bypasses site isolation, reading data from other sites","analyst_note":"","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","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-at-or-above-157.0.8103.38"],"who_is_affected":"Anyone running Google Chrome before 157.0.8103.38 is exposed, since the flaw is in the browser itself. Exploitation requires a compromised renderer process first, so the risk is mainly a chained attack that starts with a malicious page.","user_interaction":"yes","needs_special_setup":"no","severity_if_unknown":"medium"},"cost_usd":0.000672,"input_tokens":4112,"output_tokens":522,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-121063':13A,16A '-2026':12A,15A '157.0.8103.38':63C 'allow':64C 'alreadi':36B 'attack':34B,67C 'author':3A,28B,55C 'browser':17B 'bypass':8A,41B,75C 'cachestorag':2A,23B,57C 'check':29B 'chrome':1A,18B,21B,60C 'chromium':49B,83C 'compon':24B 'compromis':6A,70C 'control':37B 'craft':46B,80C 'cve':11A,14A 'desktop':19B 'flaw':4A 'googl':20B,59C 'html':47B,81C 'incorrect':27B,54C 'isol':10A,43B,77C 'let':5A,31B 'medium':52B,86C 'page':48B,82C 'prior':61C 'process':40B,73C 'rate':50B 'remot':33B,66C 'render':7A,39B,72C 'secur':84C 'sever':53B,85C 'site':9A,42B,76C 'via':44B,78C","nicknames":[],"mitigations":[],"who_affected":"Anyone running Google Chrome before 157.0.8103.38 is exposed, since the flaw is in the browser itself. Exploitation requires a compromised renderer process first, so the risk is mainly a chained attack that starts with a malicious page.","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":["browsers","chrome","desktop","medium","other"],"campaign_type":null,"first_public_at":"2026-11-03T21:17:10+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-121063","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121063","severity":null,"published_at":"2026-11-03T21:17:10+00:00","modified_at":"2026-11-03T21:17:11+00:00","first_seen_at":"2026-11-03T21:19:11+00:00","fetched_at":"2026-11-03T21:19:11+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"}