CVE-2026-7507
HighCVSS 7.5Exploitation Probability (EPSS)
Elevated risk57th percentile - higher than 57% of all known CVEs
Summary
A session fixation vulnerability was found in Keycloak's login-actions endpoints. An unauthenticated attacker can pre-create an authentication session and trick a victim into clicking a malicious link, allowing the attacker to hijack the required-action form without the victim's credentials. Successful exploitation could lead to complete account takeover, including highly privileged administrative accounts.
Risk Assessment
The risk for the organization includes the possibility of complete account takeover, especially for highly privileged accounts, potentially leading to unauthorized access to sensitive data and systems.
Recommendation
It is recommended to immediately update Keycloak to a patched version and implement CSRF protection and cookie ownership validation for login endpoints.
Other vulnerabilities in Keycloak
See all- CVE-2026-101333Low
A flaw in the Micrometer user-event metrics listener of Keycloak occurs when the listener is configured to include the idp tag. An unauthenticated attacker can send requests to the identity broker login endpoint using arbitrary provider aliases, causing the system to create an unlimited number of metric time series, leading to excessive memory consumption and degraded performance of the server and monitoring tools.
- CVE-2026-19607Medium
A flaw was found in the first-broker-login flow of the keycloak-services component. It allows an attacker to register a matching username on an external identity provider, causing a collision in Keycloak and locking out the legitimate user.
- CVE-2026-17526High
Keycloak is an open-source identity and access management solution. A vulnerability was discovered where a user with the impersonation role can impersonate a realm administrator, gaining full administrative control over the realm, including the ability to manage users, clients, and roles.
- CVE-2026-79651High
A flaw was found in the theme localization endpoints of the keycloak-services component, which is the core service responsible for authentication flows and theme management in Keycloak. The issue occurs because the system accepts arbitrary locale tags from unauthenticated requests and stores them in a permanent in-memory cache without limits. An attacker can exploit this by sending a large number of unique locale tags, eventually causing the server to run out of memory and crash.
- CVE-2026-18212High
A flaw was found in the SAML Redirect Binding implementation of Keycloak where the custom DEFLATE compression and decompression helpers fail to release native zlib memory after use. An unauthenticated attacker can exploit this by sending repeated malformed SAML requests, leading to native memory exhaustion and a denial of service.
- CVE-2026-19608Medium
A flaw was found in the group policy provider of Keycloak authorization services, which is used to manage fine-grained access control to resources. The issue occurs when the system evaluates group-based policies using tokens that only contain group names rather than full paths. If two groups in different parts of the organization share the same name, a user in the unauthorized group can be mistaken for a member of the authorized group. This can allow a user to gain unauthorized access to protected resources they should not be able to reach.
- CVE-2017-12159High
It was found that the cookie used for CSRF prevention in Keycloak was not unique to each session. An attacker could use this flaw to gain access to an authenticated user session, leading to possible information disclosure or further attacks.
- CVE-2026-118959Medium
A flaw was found in the required action provider mechanism of Keycloak. When an authorization request includes the kc_action query parameter set to a mandatory action already assigned to the user (such as profile verification or terms and conditions), Keycloak may skip these mandatory challenges and issue an authorization code.
- CVE-2026-118947Medium
A flaw was found in the UMA resource registration endpoint of the keycloak-services component. When remote resource management is enabled, an authenticated user with specific permissions can update resources they do not own by providing a target resource ID in a request.
- CVE-2026-118425Medium
A flaw was found in the secure-redirect-uris-enforcer client policy of Keycloak, an identity and access management solution. The issue occurs when the policy is configured to allow loopback addresses, as Keycloak resolves hostnames via DNS during validation. An attacker can bypass domain allowlist restrictions by using a hostname that resolves to a loopback address, potentially allowing the registration of unauthorized redirect URIs.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

