JetBrains TeamCity has an open redirect flaw in the SAML plugin that allows an attacker to direct authenticated users to arbitrary URLs. This flaw, categorized as CWE-601, can be exploited to facilitate phishing or delivery of malicious content by tricking users into visiting compromised sites. The impact is limited to user session redirection; it does not directly expose sensitive data or grant code execution, but it can indirectly aid broader attacks.

All JetBrains TeamCity installations running a version prior to 2026.1 are vulnerable. The affected component is the SAML plugin integrated into the TeamCity server.

The CVSS score of 3.1 indicates a low severity level, and the EPSS score is currently unavailable. Since the flaw is not listed in the CISA KEV catalog, there is no evidence of widespread exploitation yet. The attack vector is over the web, requiring an attacker to craft a URL that includes the redirect target. Although it does not compromise credentials or data directly, the redirect can be used as a stepping stone for phishing campaigns.