Low severity · published Aug 4, 2026
CVE-2026-18569
Keycloak-services: keycloak-services: oidc backchannel logout accepts unsigned forged logout tokens
3.7
CVSS
0.2%
EPSS
No
On KEV
Description
A flaw was found in the backchannel logout endpoint of the keycloak-services component, which is part of the Red Hat Build of Keycloak. This component handles authentication and session management for applications. The issue occurs when an OIDC identity provider is configured to skip signature validation. In this specific setup, the system incorrectly accepts logout requests that have no cryptographic signature. An attacker who knows certain technical details about a user's session can use this flaw to force that user to be logged out, potentially disrupting their work.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 16% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RH
Red Hat Build of Keycloak · Red Hat
All versions, or not specified · source: vendor
BO
Build OF Keycloak · Redhat
All versions, or not specified · source: NVD
Affected product
RH
Red Hat Build of Keycloak
Red Hat
More from Red Hat Build of Keycloak
9.8
CVE-2026-42581
Netty: HTTP/1.0 TE+CL Coexistence Bypasses Smuggling Sanitization
9.8
CVE-2026-33228
flatted: Prototype Pollution via parse()
9.1
CVE-2026-42584
Netty: HttpClientCodec response desynchronization
9.1
CVE-2026-42579
Netty: DNS Codec Input Validation Bypass in Netty (Encoder + Decoder)
8.2
CVE-2026-93569
Io.netty/netty-codec-http2: http/1 absolute-form host mismatch is translated to http/2 :authority, overriding the request-target authority