RHSA-2026:33552HighCVSS 7.4

Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update

Published
June 30, 2026
Last Modified
August 9, 2026

🔗 CVE IDs covered (3)

CVE-2026-42245 →CVE-2026-42246 →CVE-2026-42256 →

📋 Description

CVE-2026-42245 — ruby: net-imap: Net::IMAP: Denial of Service via crafted IMAP responses CVE-2026-42246 — net-imap: ruby: Net::IMAP: Information disclosure via man-in-the-middle attack bypassing TLS CVE-2026-42256 — ruby/net-imap: ruby: Net::IMAP: Denial of Service via large iteration count in SCRAM authentication

🎯 Affected products5

  • Red Hat Hardened Images
  • ruby3-4-main@aarch64 as a component of Red Hat Hardened Images
  • ruby3-4-main@noarch as a component of Red Hat Hardened Images
  • ruby3-4-main@src as a component of Red Hat Hardened Images
  • ruby3-4-main@x86_64 as a component of Red Hat Hardened Images

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Workaround: To reduce the risk of a denial of service, ensure that applications using the Net::IMAP library are configured to connect exclusively to trusted IMAP servers. Avoid connecting to untrusted or unverified IMAP services, as a hostile server can exploit this vulnerability. This operational control helps prevent exposure to malicious IMAP response processing. Workaround: As a temporary workaround, Users are strongly encouraged to switch from explicit TLS upgrading mechanisms (STARTTLS on port 143) to Implicit TLS connections (such as IMAPS on port 993). By enforcing implicit TLS via port 993 from the initial socket creation step, the connection is mathematically protected against packet injection and connection degradation tactics entirely, bypassing the vulnerable implementation path. Workaround: 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.

🔗 References (7)