{"id":"CVE-2021-37975","kind":"vulnerability","aliases":["CVE-2021-37975"],"related":[],"title":"Google Chromium V8: Google Chromium V8 Use-After-Free Vulnerability","description":"Google Chromium V8 Engine contains a use-after-free vulnerability that allows a remote attacker to potentially exploit heap corruption via a crafted HTML page. This vulnerability could affect multiple web browsers that utilize Chromium, including, but not limited to, Google Chrome, Microsoft Edge, and Opera.\n\nCISA required action: Apply updates per vendor instructions.","summary":"A use-after-free bug in the Chromium V8 JavaScript engine lets a remote attacker corrupt heap memory using a crafted HTML page. Attackers can use this to run code inside the browser, and it is actively exploited in the wild.","severity":"high","cvss":8.8,"epss":0.34887,"exploited":true,"exploited_at":"2021-11-03T00:00:00+00:00","products":[{"name":"Google Chromium V8","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["browsers","chromium","exploited","google-chrome","microsoft-edge","opera","runtime"],"not_affected_if":["already-patched-browser"],"how_to_check":"Open the browser's version page (chrome://version or edge://version) and compare the Chromium version with the fixed release in the vendor advisory.","fix":"Update Google Chrome, Microsoft Edge, Opera, or other Chromium-based browsers to the vendor's patched release, per CISA's required action.","status":"open","published_at":"2021-10-08T22:15:08+00:00","first_seen_at":"2026-10-23T19:11:53+00:00","triaged_at":"2026-10-23T21:39:36+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"runtime","confidence":0.7,"triage":{"at":"2026-10-23T21:39:36Z","model":"claude-haiku-5-5","output":{"fix":"Update Google Chrome, Microsoft Edge, Opera, or other Chromium-based browsers to the vendor's patched release, per CISA's required action.\nunknown","reach":"internet","impact":"high","summary":"A use-after-free bug in the Chromium V8 JavaScript engine lets a remote attacker corrupt heap memory using a crafted HTML page. Attackers can use this to run code inside the browser, and it is actively exploited in the wild.","category":"runtime","who_cares":["chromium","google-chrome","microsoft-edge","opera","browsers"],"confidence":0.7,"needs_auth":"no","worst_case":"Attacker runs code in the browser via a malicious web page.","analyst_note":"Fixed Chromium version and exact patched builds are not in the sources; check the Chrome Releases blog or the CISA KEV entry for the patched version.","how_to_check":"Open the browser's version page (chrome://version or edge://version) and compare the Chromium version with the fixed release in the vendor advisory.\nunknown","needs_analyst":true,"not_affected_if":["already-patched-browser"],"user_interaction":"yes","needs_special_setup":"no","severity_if_unknown":"high"},"cost_usd":0.0005,"input_tokens":2889,"output_tokens":422,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2021':13A,16A '-37975':14A,17A 'action':123C 'activ':69B 'affect':103C 'allow':86C 'appli':124C 'attack':47B,56B,89C 'browser':21B,65B,106C 'bug':37B 'chrome':26B,116C 'chromium':2A,5A,19A,22B,40B,75C,109C 'cisa':121C 'code':62B 'contain':78C 'corrupt':48B,94C 'could':102C 'craft':53B,97C 'cve':12A,15A 'edg':29B,118C 'engin':43B,77C 'exploit':23B,70B,92C 'free':10A,36B,83C 'googl':1A,4A,25B,74C,115C 'google':18A 'google-chrom':24B 'heap':49B,93C 'html':54B,98C 'includ':110C 'insid':63B 'instruct':128C 'javascript':42B 'let':44B 'limit':113C 'memori':50B 'microsoft':28B,117C 'microsoft-edg':27B 'multipl':104C 'opera':30B,120C 'page':55B,99C 'per':126C 'potenti':91C 'remot':46B,88C 'requir':122C 'run':61B 'runtim':31B 'updat':125C 'use':8A,34B,51B,58B,81C 'use-after-fre':7A,33B,80C 'util':108C 'v8':3A,6A,20A,41B,76C 'vendor':127C 'via':95C 'vulner':11A,84C,101C 'web':105C 'wild':73B","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2021-10-08T22:15:08+00:00","kev":{"dateAdded":"2021-11-03","dueDate":"2021-11-17","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2021-37975","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-37975","severity":null,"published_at":"2021-11-03T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:53+00:00","fetched_at":"2026-10-25T13:39:33+00:00","note":null},{"source":"epss","external_id":"CVE-2021-37975","url":"https://api.first.org/data/v1/epss?cve=CVE-2021-37975","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:44+00:00","fetched_at":"2026-10-23T19:13:44+00:00","note":null},{"source":"nvd","external_id":"CVE-2021-37975","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-37975","severity":null,"published_at":"2021-10-08T22:15:08+00:00","modified_at":"2026-06-17T04:01:20+00:00","first_seen_at":"2026-10-23T21:57:35+00:00","fetched_at":"2026-10-23T21:57:35+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"}