CVE-2026-15243

The record

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.

Affected packages

Related vulnerabilities

• CVE-2026-88647 A hostname verification bypass in GnuTLS v3.8.13 allows attackers to circumvent the… CWE-297
• CVE-2026-107660 FFmpeg before 8.1.3 and 9.x before 9.0.2 contains an improper certificate validation… CWE-297
• CVE-2026-19553 ssl.SSLContext.wrap_bio() didn't require the server_hostname argument to not be None if… CWE-297
• CVE-2026-91769 PHP's OpenSSL stream peer verification checks the certificate's subjectAltName entries… CWE-297
• CVE-2026-63374 AnyIO is a high level asynchronous concurrency and networking framework that works on top… CWE-297
• CVE-2026-79636 Dell SCG 5.0 Appliance versions prior to 5.36.00.16 and Dell SCG 5.0 Application versions… CWE-297
• CVE-2026-84197 In Eclipse Ditto's Node.js JavaScript client, all released versions of… CWE-297
• CVE-2026-9744 IBM Netezza Software 11.3.0.3 through Interim Fix 002 does not validate or improperly… CWE-297