RHSA-2026:35895HighCVSS 7.4

Red Hat Security Advisory: ruby security update

Published
July 6, 2026
Last Modified
August 20, 2026

🔗 CVE IDs covered (3)

CVE-2026-42245 →CVE-2026-42246 →CVE-2026-42258 →

📋 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-2026-42258 — ruby/net-imap: ruby: Net::IMAP: IMAP Command Injection via Symbol Arguments

🎯 Affected products97

  • Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)
  • ruby-0:3.3.10-11.el10_0.2.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-0:3.3.10-11.el10_0.2.ppc64le as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-0:3.3.10-11.el10_0.2.s390x as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-0:3.3.10-11.el10_0.2.src as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-0:3.3.10-11.el10_0.2.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-bundled-gems-0:3.3.10-11.el10_0.2.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-bundled-gems-0:3.3.10-11.el10_0.2.ppc64le as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-bundled-gems-0:3.3.10-11.el10_0.2.s390x as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-bundled-gems-0:3.3.10-11.el10_0.2.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-bundled-gems-debuginfo-0:3.3.10-11.el10_0.2.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-bundled-gems-debuginfo-0:3.3.10-11.el10_0.2.ppc64le as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-bundled-gems-debuginfo-0:3.3.10-11.el10_0.2.s390x as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-bundled-gems-debuginfo-0:3.3.10-11.el10_0.2.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-debuginfo-0:3.3.10-11.el10_0.2.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-debuginfo-0:3.3.10-11.el10_0.2.ppc64le as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-debuginfo-0:3.3.10-11.el10_0.2.s390x as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-debuginfo-0:3.3.10-11.el10_0.2.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-debugsource-0:3.3.10-11.el10_0.2.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-debugsource-0:3.3.10-11.el10_0.2.ppc64le as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-debugsource-0:3.3.10-11.el10_0.2.s390x as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-debugsource-0:3.3.10-11.el10_0.2.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-default-gems-0:3.3.10-11.el10_0.2.noarch as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-devel-0:3.3.10-11.el10_0.2.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-devel-0:3.3.10-11.el10_0.2.ppc64le as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-devel-0:3.3.10-11.el10_0.2.s390x as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-devel-0:3.3.10-11.el10_0.2.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • ruby-doc-0:3.3.10-11.el10_0.2.noarch as a component of Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)
  • ruby-libs-0:3.3.10-11.el10_0.2.aarch64 as a component of Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • +67 more not shown

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 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 (6)