CVE-2021-21148

Exp

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.

Published: 2021-02-09 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-21148 is rated Critical Active Threat (91.7/100): CVSS High severity, with high exploitation likelihood (EPSS 19.81%, 97th percentile). Core evidence: CISA KEV confirms active exploitation (added 2021-11-03) affecting Google / Chromium V8. a weakness (CWE-787) Unauthenticated remote administrative access may be possible. Mandatory action: The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2021-21148

Name: Google Chromium V8 Heap Buffer Overflow Vulnerability · CISA KEV detail

Exploit added: 2021-11-03

Action due: 2021-11-17

Required action: Apply updates per vendor instructions.

Exploit prediction scoring system (EPSS) score for CVE-2021-21148

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 22.31% 19.81% -2.50%
2 2026-05-27 24.87% 22.31% -2.56%
3 2026-02-11 24.87%

Full EPSS history (43 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-21148

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
8.6 6.4 [email protected]

Weakness enumeration for CVE-2021-21148

OS Trackers for CVE-2021-21148

vendor priority summary link
alpine CVE-2021-21148: 2 source package rows (nodejs, qt5-qtwebengine); 14 state rows across 14 repos (3.17-community, 3.17-main, 3.18-community, 3.18-main, 3.19-community, 3.19-main, 3.20-community, 3.20-main, 3.21-community, 3.21-main, 3.22-community, 3.22-main, edge-community, edge-main); fixed 14, open 0. https://security.alpinelinux.org/vuln/CVE-2021-21148
debian not yet assigned CVE-2021-21148 not yet assigned priority: Debian including 1 source packages (chromium), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-21148
gentoo normal CVE-2021-21148: 1 GLSA(s) (202104-08), 2 atom(s) (www-client/chromium, www-client/google-chrome); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-21148
suse high CVE-2021-21148 severity important: SUSE including 85 source package names (chromedriver-88.0.4324.150-bp152.2.59.1, chromedriver-88.0.4324.150-lp152.2.72.1, …), 324 product×package rows across 40 product lines (SUSE CaaS Platform 4.5, SUSE Enterprise Storage 7, … (40 product lines)): Known Not Affected 155, Will Not Fix 122, Fixed 47. https://www.suse.com/security/cve/CVE-2021-21148/
ubuntu medium CVE-2021-21148 medium priority: Ubuntu including 1 source packages (chromium-browser), 6 status rows across 6 suites (bionic, focal, groovy, trusty, upstream, xenial): released 3, DNE 2, not-affected 1. https://ubuntu.com/security/CVE-2021-21148

Affected software / configurations for CVE-2021-21148

Vendor Product Version Raw CPE
google chrome < 88.0.4324.150 cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References for CVE-2021-21148

URL Tags
http://packetstormsecurity.com/files/162579/Chrome-Array-Transfer-Bypass.html Third Party Advisory VDB Entry
https://chromereleases.googleblog.com/2021/02/stable-channel-update-for-desktop_4.html Release Notes
https://crbug.com/1170176 Permissions Required
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7ACWYJ74Z3YN2XH4QMUEGNBC3VXX464L/ Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AUQSMNV7INLDDSD3RKI5S5EAULX2QC7P/ Release Notes
https://security.gentoo.org/glsa/202104-08 Third Party Advisory
https://www.debian.org/security/2021/dsa-4858 Mailing List Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21148 US Government Resource
cvelogic Threat Intelligence