CVE-2026-18967
This allows an attacker who captures a valid, unused assertion to replay it multiple times.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.14%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
A flaw was found in the SAML broker component of Keycloak, an identity and access management solution. When configured as a SAML broker using the IdP-Initiated flow, Keycloak fails to enforce the OneTimeUse condition in SAML assertions. This allows an attacker who captures a valid, unused assertion to replay it multiple times. Successful exploitation could allow an attacker to hijack a user's session and gain unauthorized access to the system as that user.
- CVSS 3.1
- 8.1 HIGHCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- EPSS
- 0.14% probability · 4th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-294
- Affected
- redhat/build of keycloak · redhat/jboss enterprise application platform expansion pack
- Source
- secalert@redhat.com
References
- https://access.redhat.com/security/cve/CVE-2026-18967Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2511604Permissions Required
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.