Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.42% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-1190High confidence
Org.keycloak/keycloak-services: keycloak saml brokering: response delay due to unchecked notonorafter in subjectconfirmationdata
Red Hat · Red Hat build of Keycloak 26.4
Official source article: Red Hat RHSA-2026:3947 ↗. Check the applicable product and release in the original source.
3.1LowCVSS 3.1
Scheduled
Patch availableLow technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityLow→Operational priority:Low, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- 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 build of Keycloak 26.4 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.
Open-source package ranges2 source-attributed ranges
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
| Ecosystem and package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| Mavenorg.keycloak:keycloak-services | ECOSYSTEM: introduced 0; last affected 26.5.2 | Not stated | OSV record ↗aggregator derived · 10 Sep 2026 |
| mavenorg.keycloak:keycloak-services | <= 26.5.2 | Not stated | GitHub advisory ↗github reviewed aggregator · 6 Mar 2026 |
Low technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available01
What, why and how
A flaw was found in Keycloak's SAML brokering functionality. When Keycloak is configured as a client in a Security Assertion Markup Language (SAML) setup, it fails to validate the `NotOnOrAfter` timestamp within the `SubjectConfirmationData`. This allows an attacker to delay the expiration of SAML responses, potentially extending the time a response is considered valid and leading to unexpected session durations or resource consumption.
What
A flaw was found in Keycloak's SAML brokering functionality. When Keycloak is configured as a client in a Security Assertion Markup Language (SAML) setup, it fails to validate the `NotOnOrAfter` timestamp within the `SubjectConfirmationData`. This allows an attacker to delay the expiration of SAML responses, potentially extending the time a response is considered valid and leading to unexpected session durations or resource consumption.
Why
The product accepts XML from an untrusted source but does not validate the XML against the proper schema.
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
A flaw was found in Keycloak's SAML brokering functionality. When Keycloak is configured as a client in a Security Assertion Markup Language (SAML) setup, it fails to validate the `NotOnOrAfter` timestamp within the `SubjectConfirmationData`. This allows an attacker to delay the expiration of SAML responses, potentially extending the time a response is considered valid and leading to unexpected session durations or resource consumption.
Why
The product accepts XML from an untrusted source but does not validate the XML against the proper schema.
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 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 → Missing XML Validation → 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
- High: exploitation depends on specific conditions
- 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-112 ↗
CWE-112: Missing XML Validation. The product accepts XML from an untrusted source but does not validate the XML against the proper schema.
- 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:H/PR:N/UI:R/S:U/C:N/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.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.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.CNoneConfidentiality impact: No direct loss is represented by this metric.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
- 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.
04
Evidence and provenance
Published 26 Jan 2026 · Last source change 6 Mar 2026, 03:31 UTC · CWE-112 · Missing XML Validation
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-4670
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD not scheduled
Missing structured fields: affected versions. Missing data is not evidence of low risk; review the primary advisory.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
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.