How severe is CVE-2026-18215?

CVE-2026-18215 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-18215 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-18215?

CVE-2026-18215 affects Redhat Build Of Keycloak. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-18215?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-18215 published?

CVE-2026-18215 was published on 2026-07-31 and last updated on 2026-08-07.

CVE-2026-18215

CVE-2026-18215 is a medium-severity vulnerability in Redhat Build Of Keycloak with a CVSS 3.x base score of 6.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: Medium (CVSS 3.x base score 6.8)
EPSS exploit prediction: 0% (9th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Redhat Build Of Keycloak
Published: 2026-07-31
Last modified: 2026-08-07

Description

Keycloak provides a way to let users log in using Microsoft accounts while restricting access to a specific organization (tenant). A flaw was discovered where this restriction is ignored when using the token exchange feature. This means an attacker with a valid Microsoft token from a completely different organization could gain access to the Keycloak realm, potentially accessing sensitive data or performing unauthorized actions.

Frequently asked questions

What is CVE-2026-18215?: Keycloak provides a way to let users log in using Microsoft accounts while restricting access to a specific organization (tenant). A flaw was discovered where this restriction is ignored when using the token exchange feature. This means an attacker with a valid Microsoft token from a completely different organization could gain access to the Keycloak realm, potentially accessing sensitive data or performing unauthorized actions.
How severe is CVE-2026-18215?: CVE-2026-18215 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-18215 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-18215?: CVE-2026-18215 affects Redhat Build Of Keycloak. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-18215?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-18215 published?: CVE-2026-18215 was published on 2026-07-31 and last updated on 2026-08-07.

References

Affected products (1)

cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:*

More vulnerabilities in Redhat Build Of Keycloak

CVE-2026-15572 — High (CVSS 8.8): A flaw was found in Keycloak's Dynamic Client Registration (DCR) security policy management. The "Allowed Protocol…
CVE-2026-3047 — High (CVSS 8.8): A flaw was found in org.keycloak.broker.saml. When a disabled Security Assertion Markup Language (SAML) client is…
CVE-2026-16102 — High (CVSS 8.1): A flaw was found in the Dynamic Client Registration (DCR) component of Keycloak, an identity and access management…
CVE-2026-15573 — High (CVSS 8.1): A flaw was found in Keycloak's Authorization Services. The component responsible for matching request paths to security…
CVE-2026-1609 — High (CVSS 8.1): A flaw was found in Keycloak. When the JSON Web Token (JWT) authorization grant preview feature is enabled and a user…
CVE-2026-11800 — High (CVSS 8.1): A flaw was found in Keycloak. This JWT algorithm confusion vulnerability in the JWT Authorization Grant flow allows an…

All CVEs affecting Redhat Build Of Keycloak →

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-20317 — Critical (CVSS 10.0): As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Workload engineering…
CVE-2026-19977 — Critical (CVSS 10.0): A vulnerability was detected in EFM ipTIME A3004T 14.19.0. The affected element is the function…
CVE-2026-59500 — Critical (CVSS 10.0): CWE-287: Improper Authentication
CVE-2024-27253 — Critical (CVSS 10.0): IBM DOORS Next 7.0.3 through 7.0.3 Interim Fix 018 could allow an authenticated user to bypass security logic to…
CVE-2026-56162 — Critical (CVSS 10.0): Improper authentication in Azure SQL Database allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-62825 — Critical (CVSS 10.0): Improper authentication in Azure Key Vault allows an unauthorized attacker to elevate privileges over a network.

Browse all CWE-287 (Improper Authentication) vulnerabilities →