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Vulnerability · Published May 19, 2026 · Assigned by redhat

CVE-2026-7507Org.keycloak/keycloak-services: session fixation in oidc login flow that can lead to account takeover

High 7.5

In plain English

A high-severity authentication bypass by spoofing in Red Hat build of Keycloak 26.2 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 58% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.8%top 42.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Mavenorg.keycloak:keycloak-services26.6.2GHSA-hf67-5vvq-fm3r

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat build of Keycloak 26.2 see references
Red Hat Red Hat build of Keycloak 26.2 see references
Red Hat Red Hat build of Keycloak 26.2 see references
Red Hat Red Hat build of Keycloak 26.2.16 see references
Red Hat Red Hat build of Keycloak 26.4 see references
Red Hat Red Hat build of Keycloak 26.4 see references
Red Hat Red Hat build of Keycloak 26.4 see references
Red Hat Red Hat build of Keycloak 26.4.12 see references
Red Hat Red Hat Single Sign-On 7.6.13 see references
Red Hat Red Hat Single Sign-On 7.6 for RHEL 7 see references
Red Hat Red Hat Single Sign-On 7.6 for RHEL 8 see references
Red Hat Red Hat Single Sign-On 7.6 for RHEL 9 see references
Red Hat RHEL-8 based Middleware Containers see references

Weakness: CWE-290 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

References