Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
-
AccessCapture valid signed SAML response
-
ExploitReplay response to Central ACS endpoint
-
ExecutionCentral issues new auth token
-
ImpactAuthenticate as mapped identity in Central
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V6 - Authentication Replay attack prevention
|
| Exploitation Conditions | Exploitation requires that RHACS Central be configured to use SAML authentication (the Central SAML ACS endpoint must be in use) AND that the attacker first obtain a valid, unexpired, signed SAML response for a mapped identity - the vulnerability is the absence of assertion/response ID replay tracking on that endpoint. Limiting factors: the attacker cannot forge the response (it must be legitimately signed), the response must still be within its validity window (unexpired), and a SAML/SSO integration must be deployed - deployments using non-SAML authentication are unaffected. These prerequisites account for the HIGH attack complexity (AC:H) despite no privileges or user interaction being needed. |
| Impact | This is a moderate-to-serious authentication weakness (CWE-294, Authentication Bypass by Capture-replay) rated CVSS 7.4. The provided CVSS vector (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N) indicates a network-reachable flaw requiring no privileges and no user interaction, but with HIGH attack complexity - the critical mitigating factor. The complexity is HIGH precisely because the attacker must first obtain a valid, unexpired, signed SAML response, which is a non-trivial precondition requiring a position to capture or intercept that assertion. No EPSS score, CISA KEV listing, or public POC was supplied in the intelligence, so exploitation probability signals are entirely absent - the exploitation status is therefore 'no public exploit identified at time of analysis.' There is a notable data conflict: the input Tags label this 'Denial Of Service,' yet the CVSS vector explicitly sets A:N (no availability impact) and the description describes token minting via replay - this is an authentication/confidentiality-integrity issue, not a DoS, so the tag is mislabeled and should be disregarded. Net assessment: a credible but conditional risk that depends heavily on an attacker already having access to a signed SAML response; it is a real priority for organizations using SAML SSO with RHACS Central, but the HIGH complexity and lack of any exploitation signals place it below drop-everything urgency. |
| Exploit ScenarioDerived | An attacker positioned to capture network traffic or who otherwise obtains a valid, unexpired signed SAML response (for example via a logging sink, proxy, or browser-side capture) replays that same response to the RHACS Central SAML ACS endpoint multiple times. Because Central does not track used assertion or response identifiers, each submission yields a fresh, distinct authentication token for the mapped identity, letting the attacker establish or extend authenticated sessions as that user. No public exploit code is identified at time of analysis, and success depends on first acquiring the signed response (reflected in the HIGH attack complexity). |
Get an e-mail when this CVE is exploited, patched or re-scored. Free account.
Alert meAnalysisAIv1 – Oct 19, 2026
Red Hat Advanced Cluster Security for Kubernetes (RHACS) Central's SAML assertion consumer service (ACS) endpoint does not cache used assertion or response identifiers, so a single valid signed SAML response can be replayed to mint multiple distinct Central authentication tokens for the same mapped identity. Deployments are only exposed when Central is configured to authenticate via SAML; an attacker must first obtain a legitimately signed, unexpired SAML response - they cannot forge one - which is why the issue is rated CVSS 7.4 with high attack complexity despite requiring no privileges or user interaction. Successful replay yields full compromise of confidentiality and integrity for the impersonated identity; no public exploit code or confirmed active exploitation was identified at time of analysis, and non-SAML authentication configurations are unaffected.
RemediationAI
Patch status should be confirmed directly against the Red Hat advisory (https://access.redhat.com/security/cve/CVE-2026-103314) and the linked Bugzilla (https://bugzilla.redhat.com/show_bug.cgi?id=2543879), which carry the authoritative affected-version and fixed-build information; no vendor-released patch version was identified in the data available for this analysis, so do not assume a specific fix release. Until a fixed RHACS Central build is installed, the most effective compensating control is to stop using SAML authentication on Central and switch to an alternative supported identity provider integration (OpenShift OAuth, OIDC, or the built-in auth provider) - this fully removes exposure but requires re-enrolling users and re-testing role mappings. If SAML must remain enabled, restrict network access to the Central SAML ACS endpoint (typically /sso/providers/saml/acs on the Central route) to only the expected identity-provider egress addresses via network policy or an ingress proxy, accepting that this breaks legitimate SSO flows from any unlisted source, and ask the IdP to issue the shortest practical assertion lifetime (tight NotOnOrAfter / SessionNotOnOrAfter) so any captured response expires quickly, at the cost of more frequent re-authentication. Also reduce the chance of response capture by enforcing TLS end-to-end to Central, keeping SAML POST bodies out of proxy and application logs, and monitoring Central authentication logs for repeated token issuance from a single assertion or anomalous bursts of logins for one identity, which is a detective rather than preventive control.
Affects your stack
Find out whether the stacks and servers you run are on an affected version.
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
The flaw is an instance of CWE-294 (Authentication Bypass by Capture-replay) in the SAML 2.0 Web Browser SSO profile implementation of RHACS Central. In SAML SSO, the identity provider signs a <Response> containing an <Assertion> and posts it to the service provider's Assertion Consumer Service URL; the SAML specification requires the SP to reject any assertion whose ID has already been consumed within the assertion's validity window, typically by maintaining a replay cache keyed on AssertionID/Response ID until NotOnOrAfter expires. RHACS Central's ACS endpoint skipped that bookkeeping, so the same signed payload remains acceptable indefinitely until its own expiry timestamp passes. Because the signature is genuine, standard signature validation succeeds on every submission and each replay results in a newly issued, independent Central authentication token bound to the mapped user identity. The CPE data identifies Red Hat Advanced Cluster Security for Kubernetes 4.x as the affected stream (the CPE uses a wildcard version, so the authoritative affected-version matrix must be read from the Red Hat advisory), and the platform is a Kubernetes-native security stack whose Central component is the cluster-wide management and authentication service. Associated tags reference Denial Of Service and Kubernetes, reflecting the broader RHACS/Kubernetes context rather than a distinct DoS vector in this CVE.
Know when Kubernetes gets its next vulnerability
- Watch products and get an email when something new is published
- Check this CVE against your own stack and servers
- Exploit and PoC references, threat intelligence from 22 sources
No credit card · 7-day full trial
Severity by source
AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Network-reachable endpoint and no prior Central privileges give AV:N/PR:N, but needing a captured valid signed SAML response makes it AC:H; token issuance for an identity yields C:H/I:H, no availability impact so A:N.
Primary rating from Vendor (redhat).
CVSS VectorVendor: redhat
DescriptionCVE.org
A flaw was found in Red Hat Advanced Cluster Security for Kubernetes (RHACS). The Central SAML authentication ACS endpoint does not retain used SAML assertion or response identifiers to prevent replay. An attacker who obtains a valid, unexpired signed SAML response can submit it multiple times and receive distinct Central authentication tokens for the mapped identity.
Articles & Coverage 2
Executive ViewAI
Red Hat Advanced Cluster Security for Kubernetes (RHACS) Central has a SAML authentication weakness that could allow an attacker who obtains a legitimately signed, unexpired SAML response to replay it and impersonate the mapped identity, gaining full confidentiality and integrity access within Central. Only SAML-enabled deployments are exposed, and forging a response is not possible; no public exploit identified at time of analysis. Leadership should care because impersonation in a security management platform could expose cluster security data and permit unauthorized administrative actions for the affected identity.
No vendor-released patch identified at time of analysis; interim mitigations include restricting network access to the SAML ACS endpoint to trusted identity providers or proxies, shortening SAML assertion and Central token lifetimes, monitoring for duplicate assertion or response identifiers, and disabling SAML authentication where not required.
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
Affected Products (CPE)CVE.org
More in Kubernetes
View allA critical vulnerability in Kubernetes ingress-nginx controller allows unauthenticated attackers with pod network access
Credential-harvesting malware compromised 84 versions of 42 TanStack npm packages on 2026-05-11 via chained GitHub Actio
Kubernetes ingress-nginx contains a configuration injection vulnerability via the mirror-target and mirror-host Ingress
A security issue was discovered in ingress-nginx https://github.com/kubernetes/ingress-nginx where the `auth-url` Ingres
A security issue was discovered in ingress-nginx https://github.com/kubernetes/ingress-nginx where the `auth-tls-match-c
Kubernetes API server in all versions allow an attacker who is able to create a ClusterIP service and set the spec.exter
A security issue was discovered in Kubernetes where a user that can create pods on Windows nodes may be able to escalate
Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. Rated critical severity (CVSS 9.9), this vulne
Unauthenticated remote attackers can trigger complete database overwrites, server-side file reads, and SSRF attacks agai
The Kubernetes integration in GitLab Enterprise Edition 11.x before 11.2.8, 11.3.x before 11.3.9, and 11.4.x before 11.4
Fluentd configuration injection in the kube-logging Logging operator before 6.6.0 allows a namespace-scoped user who can
Authenticated Typebot users can abuse the webhook block (HTTP Request component) in versions prior to 3.13.1 to issue ar
EUVD-2026-104252
GHSA-xxr5-h8gc-q63j
NVD
CVE.org
EPSS
Vulnrichment
Exploit-DB