Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.76% for the current model date.
BlackTreeCVE IntelligenceRed Hat · Red Hat build of Keycloak 26.2
Official source articles: Red Hat RHSA-2026:19594 ↗ · Red Hat RHSA-2026:19595 ↗ · Red Hat RHSA-2026:19596 ↗ · Red Hat RHSA-2026:19597 ↗. Check the applicable product and release in the original source.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
| Ecosystem and package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| mavenorg.keycloak:keycloak-services | < 26.6.2 | 26.6.2 | GitHub advisory ↗github reviewed aggregator · 4 Jun 2026 |
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
The vendor explicitly identifies these products or versions as containing the fix.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Patch availableA session fixation vulnerability was found in Keycloak's login-actions endpoints. An unauthenticated attacker could exploit this flaw by pre-creating an authentication session and tricking a victim into visiting a maliciously crafted link. By leveraging the /login-actions/restart endpoint—which processes session handles without adequate CSRF protection or cookie ownership validation—an attacker can reset the authentication flow state. This causes Single Sign-On (SSO) to authenticate the victim transparently upon clicking the link, allowing the attacker to hijack the required-action form without needing the victim's credentials. A successful exploit could lead to complete account takeover, including highly privileged administrative accounts.
A session fixation vulnerability was found in Keycloak's login-actions endpoints. An unauthenticated attacker could exploit this flaw by pre-creating an authentication session and tricking a victim into visiting a maliciously crafted link. By leveraging the /login-actions/restart endpoint—which processes session handles without adequate CSRF protection or cookie ownership validation—an attacker can reset the authentication flow state. This causes Single Sign-On (SSO) to authenticate the victim transparently upon clicking the link, allowing the attacker to hijack the required-action form without needing the victim's credentials. A successful exploit could lead to complete account takeover, including highly privileged administrative accounts.
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
An attacker operating through a network path may attempt exploitation without authentication after a user interaction. If successful, the issue may bypass an access boundary or take over an account.
A session fixation vulnerability was found in Keycloak's login-actions endpoints. An unauthenticated attacker could exploit this flaw by pre-creating an authentication session and tricking a victim into visiting a maliciously crafted link. By leveraging the /login-actions/restart endpoint—which processes session handles without adequate CSRF protection or cookie ownership validation—an attacker can reset the authentication flow state. This causes Single Sign-On (SSO) to authenticate the victim transparently upon clicking the link, allowing the attacker to hijack the required-action form without needing the victim's credentials. A successful exploit could lead to complete account takeover, including highly privileged administrative accounts.
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
An attacker operating through a network path may attempt exploitation without authentication after a user interaction. If successful, the issue may bypass an access boundary or take over an account.
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
CWE-290: Authentication Bypass by Spoofing. This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
Operational remediation based on structured source evidence.
Published 19 May 2026 · Last source change 5 Oct 2026, 23:30 UTC · CWE-290 · Authentication Bypass by Spoofing
Missing structured fields: affected versions. Missing data is not evidence of low risk; review the primary advisory.