Evidence used
- No CISA KEV confirmation is currently recorded.
- A structured source references public exploit or proof-of-concept material.
- EPSS is 0.27% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-87505High confidence
Google Chrome: Incorrect Authorization
Google · Chrome
8.1HighCVSS 3.1
Within 7 days
Patch availableHigh technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:Critical, raised one band.upgradedsince 10 Sep 2026
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- 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 Chrome and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- 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 6 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 6 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 6 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 6 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-2026-87505 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitychromium-browser: Chromium: Site isolation bypass via crafted PDF file
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 the FileSystem component of Chromium. A remote attacker, who has already compromised the renderer process, could exploit an incorrect authorization vulnerability by using a specially crafted PDF file. This could allow the attacker to bypass site isolation, potentially leading to unauthorized access to data or further system compromise.
- Remediation
- No remediation text is recorded.
High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Patch available01
What, why and how
Incorrect authorization in FileSystem 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 PDF file. (Chromium security severity: Medium)
What
Incorrect authorization in FileSystem 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 PDF file. (Chromium security severity: Medium)
Why
The application performs an authorisation check, but it does not correctly enforce the required permission boundary.
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
Incorrect authorization in FileSystem 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 PDF file. (Chromium security severity: Medium)
Why
The application performs an authorisation check, but it does not correctly enforce the required permission boundary.
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 No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 Reference recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.
- Likely attack path
- a network path → Incorrect Authorization → 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-863 ↗
CWE-863: Incorrect Authorization. The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform 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:NCommon 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.ANoneAvailability impact: No direct loss is represented by this metric.- 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.
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. - Patch available
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- 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, 14:10 UTC · CWE-863 · Incorrect Authorization
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-2026-74388
Product sourceCNA
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
- Vendor guidanceAuthoritative vendor guidance changed: added patch: issues.chromium.org/517597701; added remediation: issues.chromium.org/517597701; 1 further additions.chrome-cve-admin@google.com ↗
- Before
- no authoritative guidance recorded
- After
- patch: issues.chromium.org/517597701 · remediation: issues.chromium.org/517597701 · vendor advisory: chromereleases.googleblog.com/stable-channel-update-for-desktop_0808145027.html
- 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
- 153.0.8010.36 < 153.0.8010.36 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
- Remediation statusRemediation status changed from Awaiting fix to Patch available.chrome-cve-admin@google.com ↗
- Before
- Awaiting fix
- After
- Patch available
- Public exploit evidencePublic exploit evidence changed from No public exploit to Public exploit reference.chrome-cve-admin@google.com ↗
- Before
- No public exploit
- After
- Public exploit reference
- SeveritySeverity changed from Unknown to High.CISA ADP ↗
- Before
- Unknown
- After
- High
- CVSS scoreCVSS score changed from not recorded to 8.1 (CVSS 3.1 · CISA ADP · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N).CISA ADP ↗
- Before
- not recorded
- After
- 8.1 (CVSS 3.1 · CISA ADP · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N)
- ENISA EUVD mappingEUVD-2026-74388 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-74388"}
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
CVE published
Fixed release or patch reference 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.