#VU105509 Improper access control in Keycloak - CVE-2025-1391

Vulnerability identifier: #VU105509

Vulnerability risk: Medium

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-1391

CWE-ID: CWE-284

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Keycloak
Server applications / Directory software, identity management

Vendor: Keycloak

Description

The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to improper mapping of users to organizations based solely on email/username patterns. A remote attacker can trick an organization administrator into allowing user access based on naming pattern if, for example, self-registration is enabled and unrestricted.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Keycloak: 26.0.0 - 26.1.2

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External links
https://github.com/keycloak/keycloak/security/advisories/GHSA-gvgg-2r3r-53x7

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.