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TI-2026-30573 Aliases CVE-2026-42257GHSA-hm49-wcqc-g2xg

net-imap: Command Injection via "raw" arguments to multiple commands

Priority LOW 26CWE-77Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
Present
Impact type
Code execution
Confidentiality · integrity · availability
None · High · Low
Fix status
Partial Red Hat: 5 fixed, 1 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-77.

Summary

Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.4.24, 0.5.14, and 0.6.4, several Net::IMAP commands accept a raw string argument that is sent to the server without validation or escaping. If this string is derived from user-controlled input, it may contain contain CRLF sequences, which an attacker can use to inject arbitrary IMAP commands. This issue has been patched in versions 0.4.24, 0.5.14, and 0.6.4.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00429 37th percentileScored 2026-11-07
Fix Partial net-imap (ruby): 0.4.24, 0.5.14, 0.6.4net-imap (RubyGems): 0.6.4, 0.5.14, 0.4.24Red Hat: 8 advisoriesRed Hat: 5 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
rubynet-imapbefore 0.4.24; 0.5.0 to before 0.5.14; 0.6.0 to before 0.6.40.4.24, 0.5.14, 0.6.4Patch availableCNA
—net-imap (RubyGems)0.6.0 to before 0.6.40.6.4Patch availableGHSA-hm49-wcqc-g2xg
—net-imap (RubyGems)0.5.0 to before 0.5.140.5.14Patch availableGHSA-hm49-wcqc-g2xg
—net-imap (RubyGems)before 0.4.240.4.24Patch availableGHSA-hm49-wcqc-g2xg
  • net-imap Vendorruby Affected before 0.4.24; 0.5.0 to before 0.5.14; 0.6.0 to before 0.6.4 Fixed in 0.4.24, 0.5.14, 0.6.4 Patch available CNA
  • net-imap (RubyGems) Vendor— Affected 0.6.0 to before 0.6.4 Fixed in 0.6.4 Patch available GHSA-hm49-wcqc-g2xg
  • net-imap (RubyGems) Vendor— Affected 0.5.0 to before 0.5.14 Fixed in 0.5.14 Patch available GHSA-hm49-wcqc-g2xg
  • net-imap (RubyGems) Vendor— Affected before 0.4.24 Fixed in 0.4.24 Patch available GHSA-hm49-wcqc-g2xg

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:ruby-lang:net\:\:imap:*:*:*:*:*:ruby:*:* imapVulnerableruby
  • cpe:2.3:a:ruby-lang:net\:\:imap:*:*:*:*:*:ruby:*:* Versions imap Vulnerable ·ruby

Remediation

  • Fix · CNA net-imap (ruby) Fixed in 0.4.24, 0.5.14, 0.6.4
  • Fix · GHSA-hm49-wcqc-g2xg net-imap (RubyGems) Fixed in 0.6.4 Advisory →
  • Fix · GHSA-hm49-wcqc-g2xg net-imap (RubyGems) Fixed in 0.5.14 Advisory →
  • Fix · GHSA-hm49-wcqc-g2xg net-imap (RubyGems) Fixed in 0.4.24 Advisory →

Red Hat 8 advisories

  • RHSA-2026:50827 Released 2026-08-05 · Red Hat rating Important
    ruby:4.0 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) ruby-4.0.6-34.module+el9.8.0+24564+e55418dc.aarch64::ruby:4.0, ruby-4.0.6-34.module+el9.8.0+24564+e55418dc.i686::ruby:4.0, ruby-4.0.6-34.module+el9.8.0+24564+e55418dc.ppc64le::ruby:4.0 +47
  • RHSA-2026:50828 Released 2026-08-05 · Red Hat rating Important
    ruby:3.3 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) ruby-3.3.12-8.module+el9.8.0+24568+2bbebe96.aarch64::ruby:3.3, ruby-3.3.12-8.module+el9.8.0+24568+2bbebe96.i686::ruby:3.3, ruby-3.3.12-8.module+el9.8.0+24568+2bbebe96.ppc64le::ruby:3.3 +47
  • RHSA-2026:50778 Released 2026-08-05 · Red Hat rating Important
    ruby security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) ruby-3.3.12-14.el10_2, ruby-bundled-gems-3.3.12-14.el10_2, ruby-default-gems-3.3.12-14.el10_2 +20
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) ruby-doc-3.3.12-14.el10_2
Show 5 more Red Hat advisories
  • RHSA-2026:50773 Released 2026-08-05 · Red Hat rating Important
    ruby4.0 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) ruby4.0-4.0.6-36.el10_2, ruby4.0-devel-4.0.6-36.el10_2, ruby4.0-rubygem-mysql2-0.5.7-36.el10_2 +1
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) ruby4.0-doc-4.0.6-36.el10_2
  • RHSA-2026:50728 Released 2026-08-05 · Red Hat rating Important
    ruby:3.3 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 8) ruby-3.3.12-8.module+el8.10.0+24567+c4e5368e.aarch64::ruby:3.3, ruby-3.3.12-8.module+el8.10.0+24567+c4e5368e.i686::ruby:3.3, ruby-3.3.12-8.module+el8.10.0+24567+c4e5368e.ppc64le::ruby:3.3 +47
  • RHSA-2026:40380 Released 2026-07-15 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images ruby3.3-3.3.10-23.4.hum1@aarch64, ruby3.3-3.3.10-23.4.hum1@src, ruby3.3-3.3.10-23.4.hum1@x86_64 +46
  • RHSA-2026:38694 Released 2026-07-13 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images ruby3.4-3.4.10-31.hum1@aarch64, ruby3.4-3.4.10-31.hum1@src, ruby3.4-3.4.10-31.hum1@x86_64 +46
  • RHSA-2026:36978 Released 2026-07-09 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images ruby4.0-4.0.5-35.hum1@aarch64, ruby4.0-4.0.5-35.hum1@src, ruby4.0-4.0.5-35.hum1@x86_64 +10

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat 3scale API Management Platform 2AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:50773, RHSA-2026:50778
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:50728
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:50827, RHSA-2026:50828
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:50773, RHSA-2026:50778
Red Hat Hardened ImagesFixed RHSA-2026:36978, RHSA-2026:38694, RHSA-2026:40380
Not affected: 1 product
  • Red Hat Hardened Images

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-42257
  2. 2026-10-03 Alias added: GHSA-hm49-wcqc-g2xg
  3. 2026-11-06 Affected versions changed · Red Hat

References

Advisory 2

Other 10

  • TI-2026-30563 net-imap vulnerable to STARTTLS stripping via invalid response timing CVSS 4.0HIGH 7.6
  • TI-2026-30574 net-imap: Command Injection via unvalidated Symbol inputs CVSS 4.0MEDIUM 5.8
  • TI-2026-30572 net-imap: Denial of service via high iteration count for `SCRAM-*` authentication CVSS 4.0MEDIUM 6.0
  • TI-2025-28441 net-imap rubygem vulnerable to possible DoS by memory exhaustion CVSS 4.0MEDIUM 6.0
  • TI-2026-30562 net-imap: Quadratic complexity when reading response literals CVSS 4.0LOW 2.3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences