{"id":"CVE-2026-121102","kind":"vulnerability","aliases":["CVE-2026-121102"],"related":[],"title":"Chrome: BackgroundFetch flaw lets a crafted web page bypass origin policy","description":"Missing authorization in BackgroundFetch 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: Medium)","summary":"Google Chrome before 157.0.8103.38 fails to check authorization in its BackgroundFetch feature. A remote attacker who gets a user to open a crafted HTML page can bypass web origin policy.","severity":"medium","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["android","chrome","desktop","runtime"],"not_affected_if":["patched-chrome"],"how_to_check":"- Check the Chrome version in Chrome's About page or with `chrome://version`; versions below `157.0.8103.38` are exposed.","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":"2026-11-03T21:25:23+00:00","updated_at":"2026-11-03T21:25:23+00:00","category":"runtime","confidence":0.7,"triage":{"at":"2026-11-03T21:25:23Z","model":"claude-haiku-5-5","output":{"fix":"- Google Chrome: move to `157.0.8103.38` or later.","reach":"internet","title":"Chrome: BackgroundFetch flaw lets a crafted web page bypass origin policy","impact":"medium","summary":"Google Chrome before 157.0.8103.38 fails to check authorization in its BackgroundFetch feature. A remote attacker who gets a user to open a crafted HTML page can bypass web origin policy.","audience":"everyone","category":"runtime","nicknames":[],"who_cares":["chrome","desktop","android"],"confidence":0.7,"fix_status":"available","needs_auth":"no","worst_case":"Attacker bypasses web origin policy from a crafted page","analyst_note":"","how_to_check":"- Check the Chrome version in Chrome's About page or with `chrome://version`; versions below `157.0.8103.38` are exposed.","plain_action":"Update Google Chrome to version 157.0.8103.38 or later.","needs_analyst":false,"not_affected_if":["patched-chrome"],"who_is_affected":"Anyone running Google Chrome before 157.0.8103.38 on desktop or Android is exposed when visiting a malicious page. Systems that do not use Chrome, or that run a patched version, are not affected.","user_interaction":"yes","needs_special_setup":"no","severity_if_unknown":"medium"},"cost_usd":0.000648,"input_tokens":4105,"output_tokens":476,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-121102':14A,17A '-2026':13A,16A '157.0.8103.38':25B,61C 'allow':62C 'android':18B 'attack':36B,65C 'author':29B,53C 'backgroundfetch':2A,32B,55C 'bypass':9A,48B,67C 'check':28B 'chrome':1A,19B,23B,58C 'chromium':76C 'craft':6A,44B,73C 'cve':12A,15A 'desktop':20B 'fail':26B 'featur':33B 'flaw':3A 'get':38B 'googl':22B,57C 'html':45B,74C 'let':4A 'medium':79C 'miss':52C 'open':42B 'origin':10A,50B,69C 'page':8A,46B,75C 'polici':11A,51B,70C 'prior':59C 'remot':35B,64C 'runtim':21B 'secur':77C 'sever':78C 'user':40B 'via':71C 'web':7A,49B,68C","nicknames":[],"mitigations":[],"who_affected":"Anyone running Google Chrome before 157.0.8103.38 on desktop or Android is exposed when visiting a malicious page. Systems that do not use Chrome, or that run a patched version, are not affected.","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":["android","chrome","desktop","medium","runtime"],"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-2026-121102","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121102","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"}