CVE catalog

CVE-2026-42246

Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAP#starttl

[CVE catalog]

Severity
High · CVSS 7.6CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Published
Source
[NVD] · [CVE record]
EPSS
0.31% · Oct 25, 2026

Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAP#starttls to return "successfully", without starting TLS. This issue has been patched in versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

DistributionPackageReleaseVersionStatus
Debianruby3.1bookworm3.1.2-7+deb12u1vulnerable
Debianruby3.1bookworm-security3.1.2-7+deb12u1vulnerable
Cperuby3.2Not reported3.2.3-1ubuntu0.24.04.8fixed
Cpelibruby3.2Not reported3.2.3-1ubuntu0.24.04.8fixed
Cperuby3.2-devNot reported3.2.3-1ubuntu0.24.04.8fixed
Cperuby3.2-docNot reported3.2.3-1ubuntu0.24.04.8fixed
Cperuby3.1Not reportedNot reportedvulnerable
Cpenet\Not reported0.3.10fixed
Cpenet\Not reported0.4.24fixed
Cpenet\Not reported0.5.14fixed
Cpenet\Not reported0.6.4fixed
Cpenet\Not reported0.6.4fixed
Ubunturuby2.7pro2.7.0-1vulnerable
Ubunturuby2.7pro2.7.0-2vulnerable
Ubunturuby2.7pro2.7.0-3vulnerable
Ubunturuby2.7pro2.7.0-4vulnerable
Ubunturuby2.7pro2.7.0-4ubuntu1vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.1vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.2vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.3vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.4vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.5vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.6vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.7vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.8vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.9vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.10vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.11vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.12vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.13vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.14vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.15vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.16vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.17vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.18vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.18+esm1vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.18+esm3vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.18+esm4vulnerable
Ubunturuby2.7pro2.7.0-5ubuntu1.18+esm5fixed
Ubunturuby3.022.043.0.2-5ubuntu1vulnerable
Ubunturuby3.022.043.0.2-7vulnerable
Ubunturuby3.022.043.0.2-7ubuntu2vulnerable
Ubunturuby3.022.043.0.2-7ubuntu2.1vulnerable
Ubunturuby3.022.043.0.2-7ubuntu2.2vulnerable
Ubunturuby3.022.043.0.2-7ubuntu2.3vulnerable
Ubunturuby3.022.043.0.2-7ubuntu2.4vulnerable
Ubunturuby3.022.043.0.2-7ubuntu2.5vulnerable
Ubunturuby3.022.043.0.2-7ubuntu2.6vulnerable
Ubunturuby3.022.043.0.2-7ubuntu2.7vulnerable
Ubunturuby3.022.043.0.2-7ubuntu2.8vulnerable
Ubunturuby3.022.043.0.2-7ubuntu2.10vulnerable
Ubunturuby3.022.043.0.2-7ubuntu2.11vulnerable
Ubunturuby3.022.043.0.2-7ubuntu2.12vulnerable
Ubunturuby3.022.043.0.2-7ubuntu2.13fixed
Ubunturuby3.224.043.2.3-1vulnerable
Ubunturuby3.224.043.2.3-1build2vulnerable
Ubunturuby3.224.043.2.3-1build3vulnerable
Ubunturuby3.224.043.2.3-1ubuntu0.24.04.1vulnerable
Ubunturuby3.224.043.2.3-1ubuntu0.24.04.3vulnerable
Ubunturuby3.224.043.2.3-1ubuntu0.24.04.5vulnerable
Ubunturuby3.224.043.2.3-1ubuntu0.24.04.6vulnerable
Ubunturuby3.224.043.2.3-1ubuntu0.24.04.7vulnerable
Ubunturuby3.224.043.2.3-1ubuntu0.24.04.8fixed
Ubunturuby3.326.043.3.8-2ubuntu2vulnerable
Ubunturuby3.326.043.3.8-2ubuntu3vulnerable
Ubunturuby3.326.043.3.8-2ubuntu3.1fixed
Susehawk2linux enterprise server for sap applications 16.02.7.2+git.1788518533.7d4dadd6-160000.1.1fixed
Susehawk2linux enterprise high availability extension 16.02.7.2+git.1788518533.7d4dadd6-160000.1.1fixed
Opensusehawk2leap 16.02.7.2+git.1788518533.7d4dadd6-160000.1.1fixed
Alpineruby-net-imap3.210.4.25-r0fixed

Fixed-version evidence

DistributionPackageTypeReleaseFixed versionUrgencyOriginBugs
Debianruby3.1sourcebookworm(unfixed)not yet assignedNot reportedNot reported
Cperuby3.2cpeNot reported3.2.3-1ubuntu0.24.04.8Not reportedNot reportedNot reported
Cpelibruby3.2cpeNot reported3.2.3-1ubuntu0.24.04.8Not reportedNot reportedNot reported
Cperuby3.2-devcpeNot reported3.2.3-1ubuntu0.24.04.8Not reportedNot reportedNot reported
Cperuby3.2-doccpeNot reported3.2.3-1ubuntu0.24.04.8Not reportedNot reportedNot reported
Cpenet\cpeNot reported0.3.10Not reportedNot reportedNot reported
Cpenet\cpeNot reported0.4.24Not reportedNot reportedNot reported
Cpenet\cpeNot reported0.5.14Not reportedNot reportedNot reported
Cpenet\cpeNot reported0.6.4Not reportedNot reportedNot reported
Cpenet\cpeNot reported0.6.4Not reportedNVD-CVE-2026-42246Not reported
Ubunturuby2.7debpro2.7.0-5ubuntu1.18+esm5Not reportedUSN-8478-1Not reported
Ubunturuby3.0deb22.043.0.2-7ubuntu2.13Not reportedUSN-8478-1Not reported
Ubunturuby3.2deb24.043.2.3-1ubuntu0.24.04.8Not reportedUSN-8478-1Not reported
Ubunturuby3.3deb26.043.3.8-2ubuntu3.1Not reportedUSN-8478-1Not reported
Susehawk2rpmlinux enterprise server for sap applications 16.02.7.2+git.1788518533.7d4dadd6-160000.1.1Not reportedSUSE-SU-2026:24250-1Not reported
Susehawk2rpmlinux enterprise high availability extension 16.02.7.2+git.1788518533.7d4dadd6-160000.1.1Not reportedSUSE-SU-2026:24195-1Not reported
Opensusehawk2rpmleap 16.02.7.2+git.1788518533.7d4dadd6-160000.1.1Not reportedOPENSUSE-SU-2026:22068-1Not reported
Alpineruby-net-imapapk3.210.4.25-r0Not reportedALPINE-CVE-2026-42246Not reported

OpenFactory catalog packages

[Debian 12 (Bookworm)]

  • [libruby3.1]Affected

    Source package: [ruby3.1]

    Details (4)

    • 3.1.2-7+deb12u1 · amd64 · bookworm

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

    • 3.1.2-7+deb12u1 · arm64 · bookworm

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

    • 3.1.2-7+deb12u1 · amd64 · bookworm-security

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

    • 3.1.2-7+deb12u1 · arm64 · bookworm-security

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

  • [ruby3.1]Affected
    Details (4)

    • 3.1.2-7+deb12u1 · amd64 · bookworm

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

    • 3.1.2-7+deb12u1 · arm64 · bookworm

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

    • 3.1.2-7+deb12u1 · amd64 · bookworm-security

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

    • 3.1.2-7+deb12u1 · arm64 · bookworm-security

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

  • [ruby3.1-dev]Affected

    Source package: [ruby3.1]

    Details (4)

    • 3.1.2-7+deb12u1 · amd64 · bookworm

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

    • 3.1.2-7+deb12u1 · arm64 · bookworm

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

    • 3.1.2-7+deb12u1 · amd64 · bookworm-security

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

    • 3.1.2-7+deb12u1 · arm64 · bookworm-security

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

  • [ruby3.1-doc]Affected

    Source package: [ruby3.1]

    Details (4)

    • 3.1.2-7+deb12u1 · all · bookworm

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

    • 3.1.2-7+deb12u1 · all · bookworm

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

    • 3.1.2-7+deb12u1 · all · bookworm-security

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

    • 3.1.2-7+deb12u1 · all · bookworm-security

      Affected

      nvd · ruby3.1 · debian · bookworm; nvd · ruby3.1 · debian · 12

[Debian 13 (Trixie)]

  • [libruby3.3]Affected

    Source package: [ruby3.3]

    Details (2)

    • 3.3.8-2 · amd64 · trixie

      Affected

      nvd · ruby3.3 · debian · 13

    • 3.3.8-2 · arm64 · trixie

      Affected

      nvd · ruby3.3 · debian · 13

  • [ruby3.3]Affected
    Details (2)

    • 3.3.8-2 · amd64 · trixie

      Affected

      nvd · ruby3.3 · debian · 13

    • 3.3.8-2 · arm64 · trixie

      Affected

      nvd · ruby3.3 · debian · 13

  • [ruby3.3-dev]Affected

    Source package: [ruby3.3]

    Details (2)

    • 3.3.8-2 · amd64 · trixie

      Affected

      nvd · ruby3.3 · debian · 13

    • 3.3.8-2 · arm64 · trixie

      Affected

      nvd · ruby3.3 · debian · 13

  • [ruby3.3-doc]Affected

    Source package: [ruby3.3]

    Details (2)

    • 3.3.8-2 · all · trixie

      Affected

      nvd · ruby3.3 · debian · 13

    • 3.3.8-2 · all · trixie

      Affected

      nvd · ruby3.3 · debian · 13

Observed:

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]