Vulnerability Description
Apereo CAS Client accepts any CA-trusted certificate for any hostname, provided the URL the client is calling matches the configured allowlist or regex. An attacker with a MITM position (DNS poisoning, rogue Wi-Fi, malicious proxy, etc.) can provide any CA-signed certificate for a hostname that matches the configured allowlist or regex. This can lead to intercepting the CAS exchange, capturing the Ticket-Granting Ticket (TGT), and subsequently obtaining Service Tickets on behalf of the victim. Because maintainers contact attempts were unsuccessful, vulnerabilities have only been confirmed in version 4.1.0 (Java Apereo CAS Client) and 3.6.4 (Jasig CAS Client) but may also affect other versions.
Related Weaknesses (CWE)
References
FAQ
What is CVE-2026-15243?
CVE-2026-15243 is a documented vulnerability. Apereo CAS Client accepts any CA-trusted certificate for any hostname, provided the URL the client is calling matches the configured allowlist or regex. An attacker with a MITM position (DNS poisoning...
How severe is CVE-2026-15243?
CVSS scoring is not yet available for CVE-2026-15243. Check NVD for updates.
Is there a patch for CVE-2026-15243?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.