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CVE-2026-18569

LOW 3.7

Published 2026-08-04 · Last modified 2026-08-04

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.

NO EXPLOITATION SIGNALS

No known exploitation, public exploit, or elevated probability at this time. Track for changes.

Exploitation likelihood

0.2%chance of exploitation in 30 days · 6th percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

3.7CVSS 3.1 · LOW

  • ConfidentialityNone
  • IntegrityNone
  • AvailabilityLow

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ✓Privileges: No account or privileges required
  • ✓User interaction: No user interaction needed
  • ⚠Complexity: Needs a race window or specific setup

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-18569/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-18569/poc.json

Affected

Vendors Red Hat Redhat

Products Red Hat Build Of Keycloak Red Hat Data Grid 8 Red Hat Jboss Enterprise Application Platform Expansion Pack Red Hat Single Sign On 7 Build Of Keycloak

Weakness (CWE)

  • CWE-347: Improper Verification of Cryptographic Signature

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Known Affected Software Configurations

VendorProductVersion range
RedhatBuild Of Keycloak*

All CVSS metrics

  • LOW 3.7 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
  • LOW 3.7 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

References

Advisories

Sources: NVD · CVE.org · EPSS