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Full vulnerability report · 2021
CVE-2021-21148High confidence

Google Chromium V8 Heap Buffer Overflow Vulnerability

Google · Chromium V8

8.8HighCVSS 3.1
Recommended action
Protect now

CISA confirms exploitation in the wild and lists 2021-11-17 as the remediation due date.

Fix not verified
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Critical, raised one band.upgradedsince 3 Nov 2021

Evidence used

  • CISA confirms exploitation in the wild.
  • EPSS is 19.97% for the current model date.

Compensating controls

  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Google Chromium V8 and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Alpine, Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

10 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Alpine v3.23v3.23 · communityqt5-qtwebengineVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.5.15.3_git20200401-r0Alpine Security Database ↗Source updated 11 Sep 2026
Alpine v3.23v3.23 · mainnodejsVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.14.15.5-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.22v3.22 · communityqt5-qtwebengineVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.5.15.3_git20200401-r0Alpine Security Database ↗Source updated 11 Sep 2026
Alpine v3.22v3.22 · mainnodejsVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.14.15.5-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.21v3.21 · communityqt5-qtwebengineVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.5.15.3_git20200401-r0Alpine Security Database ↗Source updated 19 Aug 2026
Alpine v3.21v3.21 · mainnodejsVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.14.15.5-r0Alpine Security Database ↗Source updated 3 Oct 2026
Debian trixietrixie · sourcechromiumVendor fix publishedDebian records a fixed source-package version for this release.88.0.4324.150-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourcechromiumVendor fix publishedDebian records a fixed source-package version for this release.88.0.4324.150-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourcechromiumVendor fix publishedDebian records a fixed source-package version for this release.88.0.4324.150-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourcechromiumVendor fix publishedDebian records a fixed source-package version for this release.88.0.4324.150-1Debian Security Tracker ↗Source updated 5 Oct 2026
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2021-8539

CISA KEV mirrored by ENISA

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.

EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 3 Nov 2021. Evidence sources: cisa_kev.
ENISA score
8.8 · CVSS 3.1
Advisory evidence
9 linked advisory records
Explicit mitigation evidence

Only statements that explicitly mention a fix, patch, update, workaround or mitigation are shown here.

  • csaf_opensuse · openSUSE-SU-2021:1016-1Security update for libqt5-qtwebengine
  • csaf_opensuse · openSUSE-SU-2021:0276-1Security update for chromium
  • csaf_opensuse · openSUSE-SU-2021:0973-1Security update for libqt5-qtwebengine
  • csaf_opensuse · openSUSE-SU-2021:0413-1Security update for opera
  • csaf_opensuse · openSUSE-SU-2021:0296-1Security update for opera
  • csaf_opensuse · openSUSE-SU-2021:0267-1Security update for chromium
Recommended actionProtect now

CISA confirms exploitation in the wild and lists 2021-11-17 as the remediation due date.

Fix not verified
01

What, why and how

Google Chromium V8 Engine contains a heap buffer overflow 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.

What

Google Chromium V8 Engine contains a heap buffer overflow 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.

Why

A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.

How

An attacker operating through a network path may attempt exploitation without authentication after a user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Google Chromium V8 Engine contains a heap buffer overflow 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.

Why

A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.

How

An attacker operating through a network path may attempt exploitation without authentication after a user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Confirmed in the wild

CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2021-11-03.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Out-of-bounds Write → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
Required interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-787 ↗

CWE-787: Out-of-bounds Write. The product writes data past the end, or before the beginning, of the intended buffer.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-787CISA KEV
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2021-8539Known-exploited evidence recorded

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.

Official EUVD record ↗
Cyber Security Agency of Singapore · English · CSA-SB-20210210Security Bulletin 10 Feb 2021

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 10 Feb 2021, published on 10 February 2021. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-103Multiples vulnérabilités dans Microsoft Edge

d?id=CVE-2021-21139 Référence CVE CVE-2021-21140 https://www.cve.org/CVERecord?id=CVE-2021-21140 Référence CVE CVE-2021-21141 https://www.cve.org/CVERecord?id=CVE-2021-21141 Référence CVE CVE-2021-21142 https://www.cve.org/CVERecord?id=CVE-2021-21142 Référence CVE CVE-2021-21143 https://www.cve.org/CVERecord?id=CVE-2021-21143 Référence CVE CVE-2021-21144 https://www.cve.org/CVERecord?id=CVE-2021-21144 Référence CVE CVE-2021-21145 https://www.cve.org/CVERecord?id=CVE-2021-21145 Référence CVE CVE-2021-21146 https://www.cve.org/CVERecord?id=CVE-2021-21146 Référence CVE CVE-2021-21147 https://www.cve.org/CVERecord?id=CVE-2021-21147 Référence CVE CVE-2021-21148 https://www.cve.org/CVERecord?id=CVE-2021-21148 Référence CVE CVE-2021-24100 https://www.cve.org/CVERecord?id=CVE-2021-24100 Référence CVE CVE-2021-24113 https://www.cve.org/CVERecord?id=CVE-2021-24113 Gestion détaillée du document le 10 février 2021 Version initiale Alertes Avis Bulletins d’actualités Mentions légales Conditions générales À propos Contact cyber.gouv.fr service-public.fr legifrance.gouv.fr info.gouv.fr france.fr info.gouv.fr/risques Premier Ministre / Secrétariat Général de la Défense et de la Sécurité Nationale / Agence nationale de la sécurité des systèmes d'information

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-089Vulnérabilité dans Microsoft Edge

Une vulnérabilité a été découverte dans Microsoft Edge. Elle permet à un attaquant de provoquer un problème de sécurité non spécifié par l'éditeur.

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-088Vulnérabilité dans Google Chrome

Une vulnérabilité a été découverte dans Google Chrome. Elle permet à un attaquant de provoquer un problème de sécurité non spécifié par l'éditeur.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-003642Google Chrome における境界外書き込みに関する脆弱性

Google Chrome には、境界外書き込みに関する脆弱性が存在します。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix not verified
Affected
Chrome: unspecified < 88.0.4324.150
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 9 Feb 2021 · Last source change 21 Oct 2025, 23:35 UTC · CWE-787 · Out-of-bounds Write

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2021-8539
Product sourceCISA KEV
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    unspecified < 88.0.4324.150 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    Chrome: unspecified < 88.0.4324.150 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Added to CISA KEV
ENISA EUVD · EUVD-2021-8539↗CISA KEV record↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2021-21148 · cve.blacktree.nl