CVE-2026-42256

A flaw was found in Net::IMAP, a Ruby library for Internet Message Access Protocol (IMAP) client functionality. A hostile server can exploit this vulnerability during SCRAM-SHA1 or SCRAM-SHA256 (Salted Challenge Response Authentication Mechanism - Secure Hash Algorithm 1 or 256) authentication by sending an excessively large iteration count value. This can lead to a computational denial-of-service attack, causing the client process to become unresponsive.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

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.