Insufficient backchannel validation in Keycloak CIBA blind SSRF
CVE-2026-1518 Published on February 2, 2026
Keycloak: blind server-side request forgery (ssrf) via ciba backchannel notification endpoint in keycloak
A flaw was found in Keycloaks CIBA feature where insufficient validation of client-configured backchannel notification endpoints could allow blind server-side requests to internal services.
Vulnerability Analysis
CVE-2026-1518 is exploitable with network access, and requires user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, with no impact on integrity, and no impact on availability.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
What is a SSRF Vulnerability?
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.
CVE-2026-1518 has been classified to as a SSRF vulnerability or weakness.
Products Associated with CVE-2026-1518
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Affected Versions
Red Hat Build of Keycloak: Red Hat Build of Keycloak: Red Hat Build of Keycloak:Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.