CVE Catalog

CVE-2026-15243

HighCVSS 7.4
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.17%

7th percentile - higher than 7% of all known CVEs

Summary

Apereo CAS Client accepts any CA-trusted certificate for any hostname, provided the URL matches the configured allowlist or regex. An attacker with MITM position can provide a CA-signed certificate for a matching hostname, intercept the CAS exchange, capture the TGT, and obtain Service Tickets on behalf of the victim. Confirmed in versions 4.1.0 (Java Apereo CAS Client) and 3.6.4 (Jasig CAS Client), but may affect other versions.

Risk Assessment

Risk of CAS authentication session interception and identity theft, potentially leading to unauthorized access to applications.

Recommendation

Upgrade Apereo CAS Client to the latest available version or implement certificate verification mechanisms (e.g., pinning).

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS