CVE-2026-15243: Improper Validation of Certificate in CAS Client
Apereo · Java Apereo CAS Client
Affected: Apereo Java Apereo CAS Client · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 17% of scored CVEs
DescriptionCVE.org
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 products2
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- Apereo · Java Apereo CAS Client4.1.0
- Apereo · Jasig CAS Client3.6.4
On the Atlas
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CoverageNo articles yet
No CyberSIXT article names CVE-2026-15243 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.