{"id":"CVE-2021-30551","published":"2021-06-15T22:15:09Z","modified":"2026-06-17T03:50:26Z","title":"Google Chromium V8 Type Confusion Vulnerability","vendor":"Google","product":"Chromium V8","tier":"core","eol":null,"description":{"text":"Type confusion in V8 in Google Chrome prior to 91.0.4472.101 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.","provenance":"source","from":"NVD"},"summary":{"text":"A type confusion flaw in the V8 JavaScript engine of Google Chrome (Chromium V8) allows heap corruption. The affected builds are those prior to 91.0.4472.101. A remote attacker who gets a victim to load a crafted HTML page can potentially exploit the heap corruption; no authentication is required, but user interaction (visiting the page) is needed.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-31T05:10:05Z"},"cvss":{"score":8.8,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.64701,"percentile":0.99242,"date":"2026-10-30","provenance":"source"},"kev":{"dateAdded":"2021-11-03","dueDate":"2021-11-17","ransomware":false,"requiredAction":"Apply updates per vendor instructions.","notes":"https://nvd.nist.gov/vuln/detail/CVE-2021-30551","provenance":"source"},"vulncheckKev":{"dateAdded":"2021-06-03","exploitedFirstSeen":"2021-06-03","ransomware":false,"evidence":[{"url":"https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit","date":"2021-06-03"},{"url":"https://blog.google/threat-analysis-group/how-we-protect-users-0-day-attacks/","date":"2021-07-14"},{"url":"https://citizenlab.ca/2021/07/hooking-candiru-another-mercenary-spyware-vendor-comes-into-focus/","date":"2021-07-15"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2021-11-03"},{"url":"https://storage.googleapis.com/gweb-uniblog-publish-prod/documents/Buying_Spying_-_Insights_into_Commercial_Surveillance_Vendors.pdf","date":"2024-02-06"},{"url":"https://assets.recordedfuture.com/content/dam/insikt-report-pdfs/2025/cta-2025-0805.pdf","date":"2025-08-04"}],"evidenceTotal":6,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"EbeeOct2026 Pt4","url":"https://otx.alienvault.com/pulse/6ad87c6c085d1e0d032d9ad9","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"}],"provenance":"machine"},"cwes":[{"id":"CWE-843","name":"Access of Resource Using Incompatible Type"},{"id":"CWE-122","name":"Heap-based Buffer Overflow"}],"references":[{"url":"https://chromereleases.googleblog.com/2021/06/stable-channel-update-for-desktop.html","tags":["Release Notes"]},{"url":"https://crbug.com/1216437","tags":["Exploit","Issue Tracking","Third Party Advisory"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ETMZL6IHCTCTREEL434BQ4THQ7EOHJ43/","tags":["Release Notes"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PAT6EOXVQFE6JFMFQF4IKAOUQSHMHL54/","tags":["Release Notes"]},{"url":"https://security.gentoo.org/glsa/202107-06","tags":["Third Party Advisory"]},{"url":"https://security.gentoo.org/glsa/202208-25","tags":["Third Party Advisory"]},{"url":"https://chromereleases.googleblog.com/2021/06/stable-channel-update-for-desktop.html","tags":["Release Notes"]},{"url":"https://crbug.com/1216437","tags":["Exploit","Issue Tracking","Third Party Advisory"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ETMZL6IHCTCTREEL434BQ4THQ7EOHJ43/","tags":["Release Notes"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PAT6EOXVQFE6JFMFQF4IKAOUQSHMHL54/","tags":["Release Notes"]},{"url":"https://security.gentoo.org/glsa/202107-06","tags":["Third Party Advisory"]},{"url":"https://security.gentoo.org/glsa/202208-25","tags":["Third Party Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30551","tags":["US Government Resource"]}],"techniques":[{"id":"T1189","name":"Drive-by Compromise","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Malicious HTML page triggers browser exploit drive-by","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page","start":61,"end":149}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1203","name":"Exploitation for Client Execution","tactics":["execution"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Exploit executes code within browser client","mappingType":"primary_impact","evidence":[{"from":"description","quote":"Type confusion in V8 in Google Chrome","start":0,"end":37}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2021-17472","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-17472","exploited":true,"exploitedSince":"2021-11-03","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":1,"skipped":0,"earliest":"2021-08-22","earliestUrl":"https://github.com/xmzyshypnc/CVE-2021-30551","repos":[{"name":"xmzyshypnc/CVE-2021-30551","url":"https://github.com/xmzyshypnc/CVE-2021-30551","stars":26,"created":"2021-08-22"}]},"first":{"date":"2021-08-22","source":"PoC-in-GitHub","url":"https://github.com/xmzyshypnc/CVE-2021-30551"},"provenance":"source"},"exploitRefs":["https://crbug.com/1216437"],"flow":[{"stage":"exploitation","techniques":["T1189"],"provenance":"ai"},{"stage":"primary","techniques":["T1203"],"provenance":"ai"}],"timeline":[{"date":"2021-06-03","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV 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listing","points":0.0,"detail":"added 1976 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":19.85,"detail":"percentile 0.9924"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"1 NVD reference tagged Exploit; 1 PoC-in-GitHub repo"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":6.16,"detail":"base score 8.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]},"lineage":{"familyId":"fam-class-google-chrome-cwe-843"}}