Evidence used
- CISA confirms exploitation in the wild.
- EPSS is 3.51% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-87491High confidence
Google Chromium V8 Out of Bounds Write Vulnerability
Google · Chromium V8
8.8HighCVSS 3.1
Mitigate now
Mitigation availableCISA confirms exploitation in the wild and lists 2026-09-23 as the remediation due date.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:Critical, raised one band.upgradedsince 9 Sep 2026
Compensating controls
- Apply the linked authoritative mitigation while planning the permanent fix.
- 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
- Confirm that the asset runs Google Chromium V8 and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Distribution package intelligence
4 package statesRelease-specific package status
Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
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 release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | chromium | Vendor fix publishedDebian records a fixed source-package version for this release. | 153.0.8010.47-2~deb13u1 | Debian Security Tracker ↗Source updated 29 Oct 2026 |
| Debian bookwormbookworm · source | chromium | Vendor fix publishedDebian records a fixed source-package version for this release. | 153.0.8010.52-1~deb12u1 | Debian Security Tracker ↗Source updated 29 Oct 2026 |
| Debian forkyforky · source | chromium | Vendor fix publishedDebian records a fixed source-package version for this release. | 153.0.8010.47-1 | Debian Security Tracker ↗Source updated 29 Oct 2026 |
| Debian sidsid · source | chromium | Vendor fix publishedDebian records a fixed source-package version for this release. | 153.0.8010.47-1 | Debian Security Tracker ↗Source updated 29 Oct 2026 |
Direct vendor intelligence
1 currentAuthoritative vendor CSAF and VEX advisories
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
CVE-2026-87491 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitychromium-browser: chromium-browser: Out of bounds write in V8
The vendor explicitly states that these products are not affected by this CVE.
- All currently supported Red Hat products
- Summary
- An out of bounds write flaw was found in the V8 component of the Chromium browser. Upstream bug(s): https://code.google.com/p/chromium/issues/detail?id=543557673
- Remediation
- No remediation text is recorded.
CISA confirms exploitation in the wild and lists 2026-09-23 as the remediation due date.
Mitigation available01
What, why and how
Google Chromium V8 contains an out of bounds write vulnerability that allows a remote attacker to execute arbitrary code inside the sandbox 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 contains an out of bounds write vulnerability that allows a remote attacker to execute arbitrary code inside the sandbox 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 execute code or commands in the affected security context.
What
Google Chromium V8 contains an out of bounds write vulnerability that allows a remote attacker to execute arbitrary code inside the sandbox 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 execute code or commands in the affected security context.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation Confirmed in the wild
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2026-09-09.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 → execute code or commands in the affected security context
- 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:HCommon 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
- After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
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. - Mitigation available
- Action
- The Cyber Centre encourages users and administrators to review the provided web links and apply any necessary updates as they become available.
- 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.
Official vendor articles1 stored document
Linked articles are downloaded and versioned as source evidence. A CVE mention or approved update relationship does not, by itself, verify a fix for every product branch.
- Chrome Releases: Stable Channel Update for Desktop →Original publisher ↗Searchable text snapshot · Captured 22 Oct 2026Chrome Releases Release updates from the Chrome team Stable Channel Update for Desktop Tuesday, September 8, 2026 The Chrome team is delighted to announce the promotion of Chrome 153 to the stable channel for Windows, Mac and Linux. This will roll out over the coming days/weeks. Chrome 153.0.8010.36 (Linux) 153.0.8010
04
Evidence and provenance
Published 9 Sept 2026 · Last source change 21 Sept 2026, 12:51 UTC · CWE-787 · Out-of-bounds Write
CVE recordCVE.org · 5.2
CVSS sourceCISA ADP
EPSS source FIRST · tracked since 2026-09-09
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-74529
Product sourceCISA KEV
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- BlackTree coverageBlackTree article coverage changed from 1 BlackTree article to 2 BlackTree articles.BlackTree editorial ↗
- Before
- 1 BlackTree article
- After
- 2 BlackTree articles
- Vendor guidanceAuthoritative vendor guidance changed: removed remediation: cyber.gc.ca/google-security-advisory-av26-904.chrome-cve-admin@google.com ↗
- Before
- remediation: cyber.gc.ca/google-security-advisory-av26-904 · vendor advisory: chromereleases.googleblog.com/stable-channel-update-for-desktop_0808145027.html
- After
- vendor advisory: chromereleases.googleblog.com/stable-channel-update-for-desktop_0808145027.html
- Remediation statusRemediation status changed from Mitigation available to Awaiting fix.chrome-cve-admin@google.com ↗
- Before
- Mitigation available
- After
- Awaiting fix
- ENISA known-exploited stateENISA EUVD now records this CVE in its known-exploited dataset.ENISA EUVD ↗
- Before
- not listed in ENISA EUVD known-exploited dataset
- After
- listed in ENISA EUVD known-exploited dataset (EUVD-2026-74529)
- BlackTree coverageBlackTree article coverage changed from no BlackTree article to 1 BlackTree article.BlackTree editorial ↗
- Before
- no BlackTree article
- After
- 1 BlackTree article
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- 153.0.8010.36 < 153.0.8010.36 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- Chrome: 153.0.8010.36 < 153.0.8010.36 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- Remediation statusRemediation status changed from Awaiting fix to Mitigation available.Canadian Centre for Cyber Security ↗
- Before
- Awaiting fix
- After
- Mitigation available
- ENISA EUVD mappingEUVD-2026-74529 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-74529"}
- CISA KEV stateCISA KEV now confirms exploitation in the wild.CISA KEV ↗
- Before
- not listed in CISA KEV
- After
- listed in CISA KEV since 2026-09-09
- Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: chromereleases.googleblog.com/stable-channel-update-for-desktop_0808145027.html.chrome-cve-admin@google.com ↗
- Before
- no authoritative guidance recorded
- After
- vendor advisory: chromereleases.googleblog.com/stable-channel-update-for-desktop_0808145027.html
- SeveritySeverity changed from Unknown to High.CISA ADP ↗
- Before
- Unknown
- After
- High
- CVSS scoreCVSS score changed from not recorded to 8.8 (CVSS 3.1 · CISA ADP · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).CISA ADP ↗
- Before
- not recorded
- After
- 8.8 (CVSS 3.1 · CISA ADP · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
CVE published
Added to CISA KEV
Remediation guidance recorded
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.