{"id":"CVE-2026-121120","kind":"vulnerability","aliases":["CVE-2026-121120"],"related":[],"title":"Chrome: Prerender input flaw lets a compromised renderer bypass origin policy","description":"Improper input validation in Prerender in Google Chrome prior to 157.0.8103.38 allowed a remote attacker who had compromised the renderer process to bypass web origin policy via a crafted HTML page. (Chromium security severity: Medium)","summary":"Google Chrome before 157.0.8103.38 mishandles input in its Prerender feature. A remote attacker who already controls the renderer process can use a crafted HTML page to bypass web origin policy.","severity":"medium","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browsers","chrome","endpoints","runtime"],"not_affected_if":["chrome-updated"],"how_to_check":"- Check the installed Chrome version in Chrome's About page or with `google-chrome --version` on Linux.\n- Compare it against `157.0.8103.38`; anything older is in the stated range.","fix":"- Google Chrome: `157.0.8103.38` or later.","status":"open","published_at":"2026-11-03T21:17:19+00:00","first_seen_at":"2026-11-03T21:19:19+00:00","triaged_at":"2026-11-03T21:24:59+00:00","updated_at":"2026-11-03T21:24:59+00:00","category":"runtime","confidence":0.6,"triage":{"at":"2026-11-03T21:24:59Z","model":"claude-haiku-5-5","output":{"fix":"- Google Chrome: `157.0.8103.38` or later.","reach":"internet","title":"Chrome: Prerender input flaw lets a compromised renderer bypass origin policy","impact":"medium","summary":"Google Chrome before 157.0.8103.38 mishandles input in its Prerender feature. A remote attacker who already controls the renderer process can use a crafted HTML page to bypass web origin policy.","audience":"everyone","category":"runtime","nicknames":[],"who_cares":["chrome","browsers","endpoints"],"confidence":0.6,"fix_status":"available","needs_auth":"unknown","worst_case":"Attacker bypasses origin policy after compromising the renderer process","analyst_note":"","how_to_check":"- Check the installed Chrome version in Chrome's About page or with `google-chrome --version` on Linux.\n- Compare it against `157.0.8103.38`; anything older is in the stated range.","plain_action":"Update Google Chrome to version 157.0.8103.38 or later.","needs_analyst":false,"not_affected_if":["chrome-updated"],"who_is_affected":"Desktop and mobile installs of Google Chrome before 157.0.8103.38 are in the stated range. The attacker must first compromise the renderer process, so this is a second-stage flaw rather than a standalone entry point. Teams that manage Chrome on endpoints should check their fleet versions.","user_interaction":"yes","needs_special_setup":"no","severity_if_unknown":"medium"},"cost_usd":0.000673,"input_tokens":4105,"output_tokens":524,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-121120':14A,17A '-2026':13A,16A '157.0.8103.38':25B,62C 'allow':63C 'alreadi':36B 'attack':34B,66C 'browser':18B 'bypass':9A,48B,74C 'chrome':1A,19B,23B,59C 'chromium':83C 'compromis':7A,69C 'control':37B 'craft':44B,80C 'cve':12A,15A 'endpoint':20B 'featur':31B 'flaw':4A 'googl':22B,58C 'html':45B,81C 'improp':52C 'input':3A,27B,53C 'let':5A 'medium':86C 'mishandl':26B 'origin':10A,50B,76C 'page':46B,82C 'polici':11A,51B,77C 'prerend':2A,30B,56C 'prior':60C 'process':40B,72C 'remot':33B,65C 'render':8A,39B,71C 'runtim':21B 'secur':84C 'sever':85C 'use':42B 'valid':54C 'via':78C 'web':49B,75C","nicknames":[],"mitigations":[],"who_affected":"Desktop and mobile installs of Google Chrome before 157.0.8103.38 are in the stated range. The attacker must first compromise the renderer process, so this is a second-stage flaw rather than a standalone entry point. Teams that manage Chrome on endpoints should check their fleet versions.","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.","pkeys":[],"ptokens":[],"labels":["browsers","chrome","endpoints","medium","runtime"],"campaign_type":null,"first_public_at":"2026-11-03T21:17:19+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-121120","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121120","severity":null,"published_at":"2026-11-03T21:17:19+00:00","modified_at":"2026-11-03T21:17:20+00:00","first_seen_at":"2026-11-03T21:19:19+00:00","fetched_at":"2026-11-03T21:19:19+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"}