CVE-2026-27586
Description
A flaw was found in Caddy, an extensible server platform. Two errors in the ClientAuthentication.provision() function can cause mutual Transport Layer Security (mTLS) client certificate authentication to silently fail open. This occurs when a Certificate Authority (CA) certificate file is missing, unreadable, or malformed. A remote attacker can exploit this to bypass the intended private CA trust boundary, allowing the server to accept any client certificate signed by any system-trusted CA and granting unauthorized access.
Statement
Red Hat Product Security has determined that this vulnerability does not affect any currently supported Red Hat product. This assessment may evolve based on further analysis and discovery. For more information about this vulnerability and the products it affects, please see the linked references.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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