6.4
MEDIUM CVSS 3.1
CVE-2026-18967
Keycloak-services: keycloak-services: saml onetimeuse assertion replay in idp-initiated broker flow
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.

INFO

Published Date :

Aug. 6, 2026, 7:16 a.m.

Last Modified :

Aug. 6, 2026, 7:16 a.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-18967 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Redhat single_sign-on
2 Redhat build_of_keycloak
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 53f830b8-0a3f-465b-8143-3b8a9948e749
CVSS 3.1 MEDIUM [email protected]
CVSS 3.1 MEDIUM MITRE-CVE
Solution
Update Keycloak to enforce OneTimeUse condition in SAML assertions to prevent session hijacking.
  • Update Keycloak to the latest version.
  • Ensure SAML broker is configured correctly.
  • Apply security patches provided by the vendor.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-18967.

URL Resource
https://access.redhat.com/security/cve/CVE-2026-18967
https://bugzilla.redhat.com/show_bug.cgi?id=2511604
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-18967 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-18967 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-18967 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 06, 2026

    Action Type Old Value New Value
    Added Affected [{'cpes': ['cpe:/a:redhat:build_keycloak:'], 'vendor': 'Red Hat', 'product': 'Red Hat Build of Keycloak', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:'], 'vendor': 'Red Hat', 'product': 'Red Hat Build of Keycloak', 'packageName': 'rhbk-keycloak-rhel9/rhbk-keycloak-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:'], 'vendor': 'Red Hat', 'product': 'Red Hat Build of Keycloak', 'packageName': 'rhbk-openshift-rhel9/rhbk-openshift-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:jbosseapxp'], 'vendor': 'Red Hat', 'product': 'Red Hat JBoss Enterprise Application Platform Expansion Pack', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/jbossnetwork/restricted/listSoftware.html', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:red_hat_single_sign_on:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Single Sign-On 7', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}]
    Added 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.
    Added CVSS V3.1 AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
    Added CWE CWE-294
    Added Reference https://access.redhat.com/security/cve/CVE-2026-18967
    Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2511604
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.