CVE-2026-15571: high-severity vulnerability in Red Hat build of Keycloak 26.6
Keycloak-services: keycloak-services: predictable account-linking hash enables account takeover via malicious oidc client
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.3epss 0.4%
A flaw was found in the legacy client-initiated account-linking endpoint of Keycloak, a widely used open-source identity and access management solution. The mechanism used to protect the account-linking process from unauthorized requests relies on a hash that can be predicted by a malicious OIDC client. By tricking a user into authenticating, an attacker-controlled client can forge a valid linking URL to connect the victim's account to an attacker's external identity. This results in a full account takeover, allowing the attacker to log in as the victim.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
Affected products
Red Hat · Red Hat build of Keycloak 26.6Red Hat · Red Hat build of Keycloak 26.6.6Red Hat · Red Hat Data Grid 8Red Hat · Red Hat JBoss Enterprise Application Platform Expansion PackRed Hat · Red Hat Single Sign-On 7Related CVEs — Red Hat build of Keycloak 26.6
In the same product, most dangerous first.
CVE-2026-18963CRITICALKeycloak-services: keycloak-services: unauthenticated account takeover via reset-credentials flow bypassEPSS 4.7%CVE-2024-1635HIGHUndertow: out-of-memory error after several closed connections with wildfly-http-client protocolEPSS 4.6%CVE-2023-5685HIGHXnio: stackoverflowexception when the chain of notifier states becomes problematically bigEPSS 3.5%CVE-2024-5971HIGHUndertow: response write hangs in case of java 17 tlsv1.3 newsessionticketEPSS 2.9%CVE-2023-3223HIGHUndertow: outofmemoryerror due to @multipartconfig handlingEPSS 2.7%CVE-2024-7885HIGHUndertow: improper state management in proxy protocol parsing causes information leakageEPSS 2.6%