Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.29% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-74240High confidence
Quay: jwt claim validation bypasses in quay federated robot and sso authentication
Red Hat · Red Hat OpenShift Update Service
5.4MediumCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 3 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, unchanged from published severity.unchanged
Compensating controls
- Apply the linked authoritative mitigation while planning the permanent fix.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Red Hat Red Hat OpenShift Update Service 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.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 3 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Red Hat Product Security: 3 affected or under-investigation product states without a fixed product state in the same current advisory
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-2026-74240 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityquay: JWT claim validation bypasses in Quay federated robot and SSO authentication
The vendor explicitly identifies these products as affected by this CVE.
- openshift-update-service/openshift-update-service-rhel8 as a component of Red Hat OpenShift Update Service
- quay/quay-rhel8 as a component of Red Hat Quay 3
- quay/quay-rhel9 as a component of Red Hat Quay 3
- Summary
- A flaw was found in Red Hat Quay's JWT (JSON Web Token) validation for federated robot accounts and single sign-on (SSO) authentication. Multiple issues related to audience verification and the enforcement of `azp` and `sub` claims were identified. These flaws could allow an attacker with a validly-signed token from the same identity provider to bypass configured security restrictions. This bypass could lead to unauthorized access by circumventing intended audience, subject, or authorized-client limitations.
- Remediation
- To mitigate this issue, Red Hat Quay administrators should ensure that federated robot authentication is configured with specific audiences to enable 'verify_aud' enforcement. Additionally, review and update existing federation configurations to explicitly include and enforce 'azp' and 'sub' claims, preventing bypasses when these claims are absent. Refer to Red Hat Quay documentation for detailed configuration steps. A restart of affected Quay services may be required after configuration changes.
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 3 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
A flaw was found in Red Hat Quay's JWT (JSON Web Token) validation for federated robot accounts and single sign-on (SSO) authentication. Multiple issues related to audience verification and the enforcement of `azp` and `sub` claims were identified. These flaws could allow an attacker with a validly-signed token from the same identity provider to bypass configured security restrictions. This bypass could lead to unauthorized access by circumventing intended audience, subject, or authorized-client limitations.
What
A flaw was found in Red Hat Quay's JWT (JSON Web Token) validation for federated robot accounts and single sign-on (SSO) authentication. Multiple issues related to audience verification and the enforcement of `azp` and `sub` claims were identified. These flaws could allow an attacker with a validly-signed token from the same identity provider to bypass configured security restrictions. This bypass could lead to unauthorized access by circumventing intended audience, subject, or authorized-client limitations.
Why
The affected component does not establish the requesting party's identity reliably before granting access.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
A flaw was found in Red Hat Quay's JWT (JSON Web Token) validation for federated robot accounts and single sign-on (SSO) authentication. Multiple issues related to audience verification and the enforcement of `azp` and `sub` claims were identified. These flaws could allow an attacker with a validly-signed token from the same identity provider to bypass configured security restrictions. This bypass could lead to unauthorized access by circumventing intended audience, subject, or authorized-client limitations.
Why
The affected component does not establish the requesting party's identity reliably before granting access.
How
An attacker operating through a network path may attempt exploitation with low privileges. 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 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 → Improper Authentication → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- 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-287 ↗
CWE-287: Improper Authentication. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
- 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:L/UI:N/S:U/C:L/I:L/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.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CLowConfidentiality impact: A successful attack can cause a limited loss.ILowIntegrity impact: A successful attack can cause a limited loss.ANoneAvailability impact: No direct loss is represented by this metric.- Post-exploitation / living off the land
- Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
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 availability varies by product
- Affected
- Action
- Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
- Workaround
- To mitigate this issue, Red Hat Quay administrators should ensure that federated robot authentication is configured with specific audiences to enable 'verify_aud' enforcement. Additionally, review and update existing federation configurations to explicitly include and enforce 'azp' and 'sub' claims, preventing bypasses when these claims are absent. Refer to Red Hat Quay documentation for detailed configuration steps. A restart of affected Quay services may be required after configuration changes.
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.
- CVE-2026-74240 - Red Hat Customer Portal →Original publisher ↗Searchable text snapshot · Captured 27 Sep 2026CVE-2026-74240 Description A flaw was found in Red Hat Quay's JWT (JSON Web Token) validation for federated robot accounts and single sign-on (SSO) authentication. Multiple issues related to audience verification and the enforcement of azp and sub claims were identified. These flaws could allow an attacker with a valid
04
Evidence and provenance
Published 14 Aug 2026 · Last source change 20 Aug 2026, 14:12 UTC · CWE-287 · Improper Authentication
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-23
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-58817
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
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 vendor advisory: access.redhat.com/CVE-2026-74240; added vendor advisory: bugzilla.redhat.com/show_bug.cgi?id=2516139.secalert@redhat.com ↗
- Before
- no authoritative guidance recorded
- After
- vendor advisory: access.redhat.com/CVE-2026-74240 · vendor advisory: bugzilla.redhat.com/show_bug.cgi?id=2516139
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
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.