RHSA-2026:35866HighCVSS 7.4

Red Hat Security Advisory: ruby:2.5 security update

Published
July 6, 2026
Last Modified
August 20, 2026

🔗 CVE IDs covered (2)

CVE-2026-42246 →CVE-2026-42258 →

📋 Description

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 products140

  • Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • ruby-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.i686 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • ruby-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.i686 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • ruby-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.src (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • ruby-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.src (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • ruby-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.x86_64 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • ruby-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.x86_64 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • ruby-debuginfo-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.i686 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • ruby-debuginfo-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.i686 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • ruby-debuginfo-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.x86_64 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • ruby-debuginfo-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.x86_64 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • ruby-debugsource-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.i686 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • ruby-debugsource-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.i686 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • ruby-debugsource-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.x86_64 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • ruby-debugsource-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.x86_64 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • ruby-devel-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.i686 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • ruby-devel-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.i686 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • ruby-devel-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.x86_64 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • ruby-devel-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.x86_64 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • ruby-doc-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.noarch (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • ruby-doc-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.noarch (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • ruby-irb-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.noarch (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • ruby-irb-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.noarch (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • ruby-libs-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.i686 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • ruby-libs-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.i686 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • ruby-libs-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.x86_64 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • ruby-libs-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.x86_64 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • ruby-libs-debuginfo-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.i686 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • ruby-libs-debuginfo-0:2.5.9-109.module+el8.4.0+24479+aaeed2c5.i686 (ruby:2.5) as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • +110 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: 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 (5)