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Full vulnerability report · 2026
CVE-2026-87433High confidence

Race condition in FileAPI in Google Chrome prior to 153.0.8010.36 allowed a remote attacker who had compromised the renderer process to bypass site isolation via a crafted HTML page

Google · Chrome

8.8HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:High, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 0.28% for the current model date.

Compensating controls

  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Google Chrome 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 30 daysRemediation target: Within 180 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

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

4 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
Debian trixietrixie · sourcechromiumVendor fix publishedDebian records a fixed source-package version for this release.153.0.8010.47-2~deb13u1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourcechromiumVendor fix publishedDebian records a fixed source-package version for this release.153.0.8010.52-1~deb12u1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourcechromiumVendor fix publishedDebian records a fixed source-package version for this release.153.0.8010.47-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourcechromiumVendor fix publishedDebian records a fixed source-package version for this release.153.0.8010.47-1Debian Security Tracker ↗Source updated 5 Oct 2026
Direct vendor intelligence

Authoritative 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.

1 current
CVE-2026-87433 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitychromium-browser: Google Chrome: Race condition allows site isolation bypass
1 known not affected

The vendor explicitly states that these products are not affected by this CVE.

  • All currently supported Red Hat products
Summary
A flaw was found in Google Chrome. A race condition in the FileAPI component allows a remote attacker, who has already compromised the renderer process, to bypass site isolation. This bypass can be achieved by providing a specially crafted HTML page.
Remediation
No remediation text is recorded.
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-2026-74318

No EUVD known-exploited evidence

Race condition in FileAPI in Google Chrome prior to 153.0.8010.36 allowed a remote attacker who had compromised the renderer process to bypass site isolation via a crafted HTML page. (Chromium security severity: Medium)

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
8.8 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
01

What, why and how

Race condition in FileAPI in Google Chrome prior to 153.0.8010.36 allowed a remote attacker who had compromised the renderer process to bypass site isolation via a crafted HTML page. (Chromium security severity: Medium)

What

Race condition in FileAPI in Google Chrome prior to 153.0.8010.36 allowed a remote attacker who had compromised the renderer process to bypass site isolation via a crafted HTML page. (Chromium security severity: Medium)

Why

The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.

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

Race condition in FileAPI in Google Chrome prior to 153.0.8010.36 allowed a remote attacker who had compromised the renderer process to bypass site isolation via a crafted HTML page. (Chromium security severity: Medium)

Why

The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.

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.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

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 → Time-of-check Time-of-use (TOCTOU) Race Condition → 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-367 ↗

CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition. The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.

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-367
A

Official authority intelligence

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

ENISA EUVD · EUVD-2026-74318Official EUVD mapping

Race condition in FileAPI in Google Chrome prior to 153.0.8010.36 allowed a remote attacker who had compromised the renderer process to bypass site isolation via a crafted HTML page. (Chromium security severity: Medium)

Official EUVD record ↗
BSI · German · WID-SEC-2026-3238Google Chrome / Microsoft Edge: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff

Ein Angreifer kann mehrere Schwachstellen in Google Chrome / Microsoft Edge ausnutzen, um nicht näher spezifizierte Angriffe durchzuführen, darunter möglicherweise die Ausführung von beliebigem Code, die Umgehung von Sicherheitsmaßnahmen, die Ausweitung von Berechtigungen, die Offenlegung sensibler Informationen, die Durchführung von XSS-Angriffen oder das Auslösen eines Denial-of-Service-Zustands.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260916Security Bulletin 16 Sep 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 16 Sep 2026, published on 16 September 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1173Multiples vulnérabilités dans Microsoft Edge

férence CERTFR-2026-AVI-1173 Titre Multiples vulnérabilités dans Microsoft Edge Date de la première version 15 septembre 2026 Date de la dernière version 15 septembre 2026 Source(s) Bulletin de sécurité Microsoft Edge CVE-2026-85892 du 11 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87536 du 11 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87429 du 14 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87430 du 14 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87431 du 14 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87432 du 14 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87433 du 14 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87434 du 14 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87435 du 14 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87436 du 14 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87437 du 14 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87439 du 14 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87440 du 14 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87441 du 14 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87442 du 14 septembre 2026 Bulletin de sécurité Microsoft Edge CVE-2026-87443 d

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1139Multiples vulnérabilités dans Google Chrome

é CVE-2026-87491 est activement exploitée. Solutions Se référer au bulletin de sécurité de l'éditeur pour l'obtention des correctifs (cf. section Documentation). Documentation Bulletin de sécurité Google Chrome du 08 septembre 2026 https://chromereleases.googleblog.com/2026/09/stable-channel-update-for-desktop_0808145027.html Référence CVE CVE-2026-87429 https://www.cve.org/CVERecord?id=CVE-2026-87429 Référence CVE CVE-2026-87430 https://www.cve.org/CVERecord?id=CVE-2026-87430 Référence CVE CVE-2026-87431 https://www.cve.org/CVERecord?id=CVE-2026-87431 Référence CVE CVE-2026-87432 https://www.cve.org/CVERecord?id=CVE-2026-87432 Référence CVE CVE-2026-87433 https://www.cve.org/CVERecord?id=CVE-2026-87433 Référence CVE CVE-2026-87434 https://www.cve.org/CVERecord?id=CVE-2026-87434 Référence CVE CVE-2026-87435 https://www.cve.org/CVERecord?id=CVE-2026-87435 Référence CVE CVE-2026-87436 https://www.cve.org/CVERecord?id=CVE-2026-87436 Référence CVE CVE-2026-87437 https://www.cve.org/CVERecord?id=CVE-2026-87437 Référence CVE CVE-2026-87438 https://www.cve.org/CVERecord?id=CVE-2026-87438 Référence CVE CVE-2026-87439 https://www.cve.org/CVERecord?id=CVE-2026-87439 Référence CVE CVE-2026-87440 https://www.cve.org/CVERecord?id=CVE-2026-87440 Référence CVE CVE-2026-87441 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-033091GoogleのGoogle ChromeにおけるTime-of-check Time-of-use (TOCTOU) 競合状態の脆弱性

Google Chrome 153.0.8010.36 より前のバージョンの FileAPI における競合状態により、レンダラープロセスが侵害される可能性があり、リモート攻撃者は細工された HTML ページを介してサイト分離を回避できる脆弱性が存在しました。(Chromium セキュリティ重大度:中)

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: 153.0.8010.36 < 153.0.8010.36
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.
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 26 Sep 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 10 Sept 2026, 15:35 UTC · CWE-367 · Time-of-check Time-of-use (TOCTOU) Race Condition

CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-09-09
European sourceENISA EUVD · EUVD-2026-74318
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD modified after enrichment

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

Material change intelligence

What changed after publication

View recent updates ↗
  1. ENISA EUVD mappingEUVD-2026-74318 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2026-74318"}
    ENISA EUVD ↗
  2. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
  3. Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: chromereleases.googleblog.com/stable-channel-update-for-desktop_0808145027.html.
    Before
    no authoritative guidance recorded
    After
    vendor advisory: chromereleases.googleblog.com/stable-channel-update-for-desktop_0808145027.html
    chrome-cve-admin@google.com ↗
  4. SeveritySeverity changed from Unknown to High.
    Before
    Unknown
    After
    High
    NIST NVD ↗
  5. CVSS scoreCVSS score changed from not recorded to 8.8 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).
    Before
    not recorded
    After
    8.8 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)
    NIST NVD ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
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-2026-87433 · cve.blacktree.nl