A flaw was found in Keycloak's URL validation logic during redirect operations. By crafting a malicious request, an attacker could bypass validation to redirect users to unauthorized URLs, potentially leading to the exposure of sensitive information within the domain or facilitating further attacks. This vulnerability specifically affects Keycloak clients configured with a wildcard (*) in the "Valid Redirect URIs" field and requires user interaction to be successfully exploited. The issue stems from a discrepancy in how Keycloak and the underlying Java URI implementation handle the user-info component of a URL. If a malicious redirect URL is constructed using multiple @ characters in the user-info section, Java's URI parser fails to extract the user-info, leaving only the raw authority field. Consequently, Keycloak's validation check fails to detect the malformed user-info, falls back to a wildcard comparison, and incorrectly permits the malicious redirect.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - A flaw was found in Keycloak's URL validation logic during redirect operations. By crafting a malicious
    request, an attacker could bypass validation to redirect users to unauthorized URLs, potentially leading
    to the exposure of sensitive information within the domain or facilitating further attacks. This
    vulnerability specifically affects Keycloak clients configured with a wildcard (*) in the "Valid Redirect
    URIs" field and requires user interaction to be successfully exploited. The issue stems from a discrepancy
    in how Keycloak and the underlying Java URI implementation handle the user-info component of a URL. If a
    malicious redirect URL is constructed using multiple @ characters in the user-info section, Java's URI
    parser fails to extract the user-info, leaving only the raw authority field. Consequently, Keycloak's
    validation check fails to detect the malformed user-info, falls back to a wildcard comparison, and
    incorrectly permits the malicious redirect. (CVE-2026-7504)

Keycloak versions installed prior to 26.6.2 are affected by multiple vulnerabilities, including:

  - A flaw was found in Keycloak's redirect URI validation logic. An attacker can bypass     validation to redirect users to malicious sites, potentially leading to phishing attacks and     credential theft. (CVE-2026-7504)

  - A session fixation vulnerability exists in the OIDC login flow. An unauthenticated attacker     can pre-create sessions leading to account takeover if a user logs in using the attacker's     session. (CVE-2026-7507)

  - A flaw was found in Keycloak's SAML endpoint processing. A crafted XML request to the SAML     endpoint can cause a denial of service by consuming excessive server resources. (CVE-2026-7307)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
442646	SCA: security update for org.keycloak:keycloak-services (GHSA-rp95-xpg9-c2cq)	Tenable Cloud Security	SCA Checks	high
442646	SCA: security update for org.keycloak:keycloak-services (GHSA-rp95-xpg9-c2cq)	Tenable Self-Hosted Container Security	SCA Checks	high
316461	Keycloak < 26.6.2 Multiple Vulnerabilities	Nessus	Misc.	medium

Detections

Analytics

CVE-2026-7504

high

Tenable Plugins

high

high

medium