CVE-2026-18212 Keycloak - Denial of Service

Keycloak contains a denial of service caused by failure to release native zlib memory in SAML Redirect Binding compression helpers, letting unauthenticated attackers exhaust native memory via repeated malformed SAML requests.

CVSS base score 7.5 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.52% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Denial of Service
Impact
Denial Of Service
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
16 September 2026
Updated
15 October 2026
Weakness
CWE-401

Vendor fix

Update to the latest version of Keycloak.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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