What’s Vulnerable › Vulnerabilities

CVE-2023-6787: Keycloak: session hijacking via re-authentication

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2024-04-25 · updated 2026-06-17
• Weakness: CWE-287

Description

A flaw was found in Keycloak that occurs from an error in the re-authentication mechanism within org.keycloak.authentication. This flaw allows hijacking an active Keycloak session by triggering a new authentication process with the query parameter "prompt=login," prompting the user to re-enter their credentials. If the user cancels this re-authentication by selecting "Restart login," an account takeover may occur, as the new session, with a different SUB, will possess the same SID as the previous session.

Affected products

• Red Hat build of Keycloak 26.4: all versions
• Keycloak: before 22.0.10; from 23.0.0 before 24.0.3 — fixed in 22.0.10, 24.0.3

How to fix

Upgrade to a fixed version: Keycloak 22.0.10, 24.0.3. Check the vendor advisory for mitigations.

References

• https://access.redhat.com/errata/RHSA-2024:1867
• https://access.redhat.com/errata/RHSA-2024:1868
• https://access.redhat.com/security/cve/CVE-2023-6787
• https://bugzilla.redhat.com/show_bug.cgi?id=2254375
• https://github.com/keycloak/keycloak/security/advisories/GHSA-c9h6-v78w-52wj
• https://access.redhat.com/errata/RHSA-2024:1867
• https://access.redhat.com/errata/RHSA-2024:1868
• https://access.redhat.com/security/cve/CVE-2023-6787
• https://bugzilla.redhat.com/show_bug.cgi?id=2254375

Get alerted when CVE-2023-6787 or the next vulnerability affects your stack