{"id":"CVE-2021-21148","published":"2021-02-09T16:15:12Z","modified":"2026-06-17T03:34:54Z","title":"Google Chromium V8 Heap Buffer Overflow Vulnerability","vendor":"Google","product":"Chromium V8","tier":"core","eol":null,"description":{"text":"Heap buffer overflow in V8 in Google Chrome prior to 88.0.4324.150 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.","provenance":"source","from":"NVD"},"summary":{"text":"A heap buffer overflow in the V8 JavaScript engine of Google Chrome (Chromium V8) allows heap memory corruption. An attacker who can get a victim to load a crafted HTML page can potentially exploit it remotely, with no authentication and only user interaction required.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:10:36Z"},"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":0.19968,"percentile":0.97428,"date":"2026-10-29","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-2021-21148","provenance":"source"},"vulncheckKev":{"dateAdded":"2021-01-24","exploitedFirstSeen":"2021-01-24","ransomware":false,"evidence":[{"url":"https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit","date":"2021-01-24"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2021-11-03"}],"evidenceTotal":2,"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":"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"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-787","name":"Out-of-bounds Write"},{"id":"CWE-122","name":"Heap-based Buffer Overflow"}],"references":[{"url":"http://packetstormsecurity.com/files/162579/Chrome-Array-Transfer-Bypass.html","tags":["Third Party Advisory","VDB Entry"]},{"url":"https://chromereleases.googleblog.com/2021/02/stable-channel-update-for-desktop_4.html","tags":["Release Notes"]},{"url":"https://crbug.com/1170176","tags":["Permissions Required"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7ACWYJ74Z3YN2XH4QMUEGNBC3VXX464L/","tags":["Release Notes"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AUQSMNV7INLDDSD3RKI5S5EAULX2QC7P/","tags":["Release Notes"]},{"url":"https://security.gentoo.org/glsa/202104-08","tags":["Third Party Advisory"]},{"url":"https://www.debian.org/security/2021/dsa-4858","tags":["Mailing List","Third Party Advisory"]},{"url":"http://packetstormsecurity.com/files/162579/Chrome-Array-Transfer-Bypass.html","tags":["Third Party Advisory","VDB Entry"]},{"url":"https://chromereleases.googleblog.com/2021/02/stable-channel-update-for-desktop_4.html","tags":["Release Notes"]},{"url":"https://crbug.com/1170176","tags":["Permissions Required"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7ACWYJ74Z3YN2XH4QMUEGNBC3VXX464L/","tags":["Release Notes"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AUQSMNV7INLDDSD3RKI5S5EAULX2QC7P/","tags":["Release Notes"]},{"url":"https://security.gentoo.org/glsa/202104-08","tags":["Third Party Advisory"]},{"url":"https://www.debian.org/security/2021/dsa-4858","tags":["Mailing List","Third Party Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21148","tags":["US Government Resource"]}],"techniques":[{"id":"T1059.007","name":"JavaScript","tactics":["execution"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Buffer Overflow","mappingType":"exploitation_technique","evidence":[],"comment":"CVE-2021-21148 allows an adversary to use JavaScript to exploit the Chromium browser V8 JavaScript engine which allows for a write into the heap.","confidence":"high"},{"id":"T1203","name":"Exploitation for Client Execution","tactics":["execution"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Buffer Overflow","mappingType":"primary_impact","evidence":[],"comment":"CVE-2021-21148 allows an adversary to use JavaScript to exploit the Chromium browser V8 JavaScript engine which allows for a write into the heap.","confidence":"high"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2021-8539","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-8539","exploited":true,"exploitedSince":"2021-11-03","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":1,"skipped":0,"earliest":"2021-02-07","earliestUrl":"https://github.com/Grayhaxor/CVE-2021-21148","repos":[{"name":"Grayhaxor/CVE-2021-21148","url":"https://github.com/Grayhaxor/CVE-2021-21148","stars":2,"created":"2021-02-07"}]},"first":{"date":"2021-02-07","source":"PoC-in-GitHub","url":"https://github.com/Grayhaxor/CVE-2021-21148"},"provenance":"source"},"exploitRefs":["http://packetstormsecurity.com/files/162579/Chrome-Array-Transfer-Bypass.html"],"flow":[{"stage":"exploitation","techniques":["T1059.007"],"provenance":"source"},{"stage":"primary","techniques":["T1203"],"provenance":"source"}],"timeline":[{"date":"2021-01-24","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit","provenance":"source"},{"date":"2021-02-07","kind":"exploit-public","label":"First public exploit: PoC-in-GitHub","url":"https://github.com/Grayhaxor/CVE-2021-21148","provenance":"source"},{"date":"2021-02-09","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21148","provenance":"source"},{"date":"2021-11-03","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2021-11-03","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-8539","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":"PoC-in-GitHub","daysToKev":267},"priority":{"score":68.6,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 2104 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":19.49,"detail":"percentile 0.9743"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"1 NVD exploit link; 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-787"}}