{"id":"CVE-2026-121217","kind":"vulnerability","aliases":["CVE-2026-121217"],"related":[],"title":"Chrome: streaming use-after-free lets nearby attacker run code in sandbox","description":"Use after free in Streaming in Google Chrome prior to 157.0.8103.38 allowed an adjacent attacker to execute arbitrary code inside the sandbox via crafted network traffic. (Chromium security severity: Low)","summary":"A use-after-free bug in Chrome's Streaming component lets an attacker on the same network run code inside the browser sandbox via crafted network traffic. Chromium rates the severity Low.","severity":"low","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browser","chrome","desktop","runtime"],"not_affected_if":["chrome-158-or-later"],"how_to_check":"- Check the Chrome version in chrome://settings/help and compare it with `157.0.8103.38`.\n- Confirm whether the Chrome build in use is older than `157.0.8103.38`.","fix":"- Google Chrome: `157.0.8103.38` or later.","status":"open","published_at":"2026-11-03T21:17:31+00:00","first_seen_at":"2026-11-03T21:19:27+00:00","triaged_at":"2026-11-03T21:22:33+00:00","updated_at":"2026-11-03T21:22:33+00:00","category":"runtime","confidence":0.6,"triage":{"at":"2026-11-03T21:22:33Z","model":"claude-haiku-5-5","output":{"fix":"- Google Chrome: `157.0.8103.38` or later.","reach":"network","title":"Chrome: streaming use-after-free lets nearby attacker run code in sandbox","impact":"medium","summary":"A use-after-free bug in Chrome's Streaming component lets an attacker on the same network run code inside the browser sandbox via crafted network traffic. Chromium rates the severity Low.","audience":"everyone","category":"runtime","nicknames":[],"who_cares":["chrome","desktop","browser"],"confidence":0.6,"fix_status":"available","needs_auth":"no","worst_case":"code runs inside the browser sandbox on the victim's machine","analyst_note":"","how_to_check":"- Check the Chrome version in chrome://settings/help and compare it with `157.0.8103.38`.\n- Confirm whether the Chrome build in use is older than `157.0.8103.38`.","plain_action":"Update Google Chrome to version 157.0.8103.38 or later.","needs_analyst":false,"not_affected_if":["chrome-158-or-later"],"who_is_affected":"Anyone running a Chrome version older than 157.0.8103.38 on a desktop or laptop is exposed, since the attacker must be on an adjacent network. The sources do not say whether Streaming needs a non-default feature, so exposure in unusual setups is unknown. Machines already on the fixed version can skip it.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"low"},"cost_usd":0.000672,"input_tokens":4101,"output_tokens":524,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-121217':16A,19A '-2026':15A,18A '157.0.8103.38':67C 'adjac':70C 'allow':68C 'arbitrari':74C 'attack':9A,37B,71C 'browser':20B,46B 'bug':29B 'chrome':1A,21B,31B,64C 'chromium':52B,83C 'code':11A,43B,75C 'compon':34B 'craft':49B,80C 'cve':14A,17A 'desktop':22B 'execut':73C 'free':6A,28B,59C 'googl':63C 'insid':44B,76C 'let':7A,35B 'low':56B,86C 'nearbi':8A 'network':41B,50B,81C 'prior':65C 'rate':53B 'run':10A,42B 'runtim':23B 'sandbox':13A,47B,78C 'secur':84C 'sever':55B,85C 'stream':2A,33B,61C 'traffic':51B,82C 'use':4A,26B,57C 'use-after-fre':3A,25B 'via':48B,79C","nicknames":[],"mitigations":[],"who_affected":"Anyone running a Chrome version older than 157.0.8103.38 on a desktop or laptop is exposed, since the attacker must be on an adjacent network. The sources do not say whether Streaming needs a non-default feature, so exposure in unusual setups is unknown. Machines already on the fixed version can skip it.","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":["browser","chrome","desktop","low","runtime"],"campaign_type":null,"first_public_at":"2026-11-03T21:17:31+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-121217","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121217","severity":null,"published_at":"2026-11-03T21:17:31+00:00","modified_at":"2026-11-03T21:17:31+00:00","first_seen_at":"2026-11-03T21:19:27+00:00","fetched_at":"2026-11-03T21:19:27+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"}