{"id":"CVE-2026-121250","kind":"vulnerability","aliases":["CVE-2026-121250"],"related":[],"title":"Chrome: extension use-after-free lets a crafted extension escape the sandbox","description":"Use after free in Extensions in Google Chrome prior to 157.0.8103.38 allowed a remote attacker leveraging social engineering to potentially execute arbitrary code outside the sandbox via a crafted Chrome extension. (Chromium security severity: High)","summary":"A use-after-free bug in Chrome's Extensions component can be triggered by a crafted Chrome extension that a victim is tricked into installing. A successful attacker could potentially run code outside Chrome's sandbox.","severity":"high","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browsers","chrome","desktop","runtime"],"not_affected_if":["chrome-up-to-date","no-untrusted-extensions"],"how_to_check":"- Check the Chrome version with `chrome://settings/help` and compare it to `157.0.8103.38`\n- Review installed extensions at `chrome://extensions` for anything unfamiliar","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":"2026-11-03T21:21:00+00:00","updated_at":"2026-11-03T21:21:00+00:00","category":"runtime","confidence":0.7,"triage":{"at":"2026-11-03T21:21:00Z","model":"claude-haiku-5-5","output":{"fix":"- Google Chrome: move to `157.0.8103.38` or later","reach":"internet","title":"Chrome: extension use-after-free lets a crafted extension escape the sandbox","impact":"high","summary":"A use-after-free bug in Chrome's Extensions component can be triggered by a crafted Chrome extension that a victim is tricked into installing. A successful attacker could potentially run code outside Chrome's sandbox.","audience":"everyone","category":"runtime","nicknames":[],"who_cares":["chrome","browsers","desktop"],"confidence":0.7,"fix_status":"available","needs_auth":"no","worst_case":"Code runs outside the browser sandbox on the victim's machine.","analyst_note":"Confirm the Chromium release notes and CVE entry for the fixed version and whether it is exploited in the wild.","how_to_check":"- Check the Chrome version with `chrome://settings/help` and compare it to `157.0.8103.38`\n- Review installed extensions at `chrome://extensions` for anything unfamiliar","plain_action":"Update Google Chrome to version 157.0.8103.38 or later, and only install extensions you trust.","needs_analyst":true,"not_affected_if":["chrome-up-to-date","no-untrusted-extensions"],"who_is_affected":"Anyone running Google Chrome before 157.0.8103.38, including desktop installs on any platform the sources cover. Exposure depends on a user being socially engineered into installing a crafted extension, so teams can focus on managed browser fleets and developer machines. Users who cannot update Chrome should not rely on extension restrictions alone.","user_interaction":"yes","needs_special_setup":"no","severity_if_unknown":"high"},"cost_usd":0.000709,"input_tokens":4112,"output_tokens":596,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-121250':16A,19A '-2026':15A,18A '157.0.8103.38':71C 'allow':72C 'arbitrari':82C 'attack':52B,75C 'browser':20B 'bug':29B 'chrome':1A,21B,31B,41B,58B,68C,90C 'chromium':92C 'code':56B,83C 'compon':34B 'could':53B 'craft':9A,40B,89C 'cve':14A,17A 'desktop':22B 'engin':78C 'escap':11A 'execut':81C 'extens':2A,10A,33B,42B,65C,91C 'free':6A,28B,63C 'googl':67C 'high':95C 'instal':49B 'let':7A 'leverag':76C 'outsid':57B,84C 'potenti':54B,80C 'prior':69C 'remot':74C 'run':55B 'runtim':23B 'sandbox':13A,60B,86C 'secur':93C 'sever':94C 'social':77C 'success':51B 'trick':47B 'trigger':37B 'use':4A,26B,61C 'use-after-fre':3A,25B 'via':87C 'victim':45B","nicknames":[],"mitigations":[],"who_affected":"Anyone running Google Chrome before 157.0.8103.38, including desktop installs on any platform the sources cover. Exposure depends on a user being socially engineered into installing a crafted extension, so teams can focus on managed browser fleets and developer machines. Users who cannot update Chrome should not rely on extension restrictions alone.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"everyone","plain_action":"Update Google Chrome to version 157.0.8103.38 or later, and only install extensions you trust.","pkeys":[],"ptokens":[],"labels":["browsers","chrome","desktop","high","runtime"],"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-2026-121250","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121250","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"}