Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessIdentify exposed Keycloak SAML ECP endpoint
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DeliverySend crafted SOAP requests with enumerated client IDs
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ExploitObserve distinct faultstring values per client
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ExecutionMap client IDs to protocol types
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ImpactUse reconnaissance data for targeted follow-on attack
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A10:2025 - Mishandling of Exceptional Conditions
ASVS 5.0
V16 - Security Logging and Error Handling Error message sanitization
MITRE ATT&CK
1 technique across 1 tactic: Discovery The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | The SAML ECP endpoint must be enabled and reachable by the attacker - this endpoint is a specific SAML profile feature and may not be active in all deployments, particularly those using only OIDC or standard SAML SP flows. The CVSS vector (AV:N/AC:L/PR:N/UI:N) confirms that beyond network reachability, no authentication, specific privileges, user interaction, or elevated complexity is required. Limiting factors include: deployments that have disabled the SAML ECP profile, network perimeter controls that restrict access to Keycloak's authentication endpoints, and environments using OIDC exclusively (no SAML configuration at all). The vulnerability does not grant code execution or credential access - it is limited to disclosing whether a given client ID maps to a SAML or non-SAML protocol type. |
| Impact | The CVSS base score of 5.3 (Medium) reflects a network-accessible, low-complexity, unauthenticated attack with a limited confidentiality impact (C:L) and no integrity or availability impact (I:N/A:N). The attack vector (AV:N/AC:L/PR:N/UI:N) means any instance with the SAML ECP endpoint reachable over a network is exposed without any prerequisite conditions. EPSS data was not provided in the input and cannot be inferred; this represents a gap in the risk picture. The vulnerability is not in the CISA KEV catalog and no public exploit code has been identified, which lowers urgency compared to other Medium-CVSS issues. However, the practical risk is meaningful in reconnaissance contexts: leaking client protocol mappings assists attackers in profiling the IAM environment and narrowing attack surface for follow-on campaigns. The absence of authentication requirements means automated scanning tools could enumerate this at scale. Overall, this is a real but limited-scope issue - not a priority for emergency patching, but warrants remediation within a normal patch cycle given the zero-barrier exploitation path. |
| Exploit ScenarioDerived | An unauthenticated attacker discovers a publicly accessible Keycloak instance and submits a series of SOAP requests to the SAML ECP endpoint, cycling through candidate client IDs and recording the specific faultstring returned for each. By correlating distinct error messages to protocol types, the attacker builds a map of which client IDs correspond to SAML versus OIDC configurations, enabling more targeted follow-on attacks against specific clients or application integrations. No exploit code is publicly available, but the attack requires only standard HTTP tooling and observation of response text differences. |
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Alert meAnalysisAIv1 – May 28, 2026
Information disclosure in Red Hat Build of Keycloak exposes client protocol type to unauthenticated remote attackers via error message enumeration. By submitting specially crafted SOAP requests targeting the SAML ECP (Enhanced Client or Proxy) endpoint with varying client IDs, an attacker can observe distinct faultstring values in server responses and map which clients use which protocol types. No authentication, user interaction, or elevated privileges are required, and the CVSS vector (AV:N/AC:L/PR:N/UI:N) confirms exploitation is straightforward against any exposed instance. No public exploit code has been identified and this CVE is not listed in the CISA KEV catalog at time of analysis.
RemediationAI
The primary remediation is to apply the vendor-released patch per the Red Hat security advisory at https://access.redhat.com/security/cve/CVE-2026-9794; however, no exact fixed version number was included in the available input data, so administrators should consult that advisory directly to identify the target upgrade version. Until patching is possible, a practical compensating control is to restrict network access to the SAML ECP endpoint (typically /auth/realms/{realm}/protocol/saml/clients/saml-ecp or equivalent path) via WAF rules or reverse proxy ACLs, limiting access to known client IP ranges only - this does not eliminate the vulnerability but removes external attacker access to the vulnerable endpoint. If SAML ECP is not actively required for any clients, disabling the ECP profile entirely at the realm level eliminates the attack surface without functional impact to OIDC or standard SAML SP clients. Note that disabling ECP will break thick-client SAML authentication flows that rely on it.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in maven
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
The affected product is Red Hat Build of Keycloak, an enterprise identity and access management solution based on the upstream Keycloak project (CPE: cpe:2.3:a:red_hat:red_hat_build_of_keycloak:*:*:*:*:*:*:*:*). The vulnerability involves the SAML ECP (Security Assertion Markup Language Enhanced Client or Proxy) endpoint, which accepts SOAP-formatted XML messages to facilitate authentication for thick clients that cannot handle HTTP redirects. The root cause is classified as CWE-209 - Generation of Error Message Containing Sensitive Information - meaning the server produces different, distinguishable faultstring error messages depending on internal state (in this case, the resolved client's protocol type). This differential error response pattern enables an oracle-style enumeration attack: an attacker iterates over client IDs and classifies each by the specific error text returned, leaking configuration data that should not be externally observable.
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Primary rating from Vendor (redhat).
CVSS VectorVendor: redhat
DescriptionCVE.org
A flaw was found in Keycloak. A remote, unauthenticated attacker can exploit this vulnerability by sending specially crafted SOAP requests to the SAML ECP (Security Assertion Markup Language Enhanced Client or Proxy) endpoint with varying client IDs. By observing distinct faultstrings in the responses, the attacker can determine the client's protocol type, leading to information disclosure.
Blast Radius
ecosystem impact- 50 maven packages depend on org.keycloak:keycloak-services (22 direct, 28 indirect)
Ecosystem-wide dependent count for version 26.5.0.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Affected Products (CPE)CVE.org
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