net-imap: Command Injection via unvalidated Symbol inputs
Priority LOW 27CWE-77Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- Code execution
- Confidentiality · integrity · availability
- None · High · Low
- Fix status
- Partial Red Hat: 20 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, symbol arguments to commands are vulnerable to a CRLF Injection / IMAP Command injection via Symbol arguments passed to 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 0.00783 56th 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: 20 advisoriesRed Hat: 20 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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| ruby | net-imap | before 0.4.24; 0.5.0 to before 0.5.14; 0.6.0 to before 0.6.4 | 0.4.24, 0.5.14, 0.6.4 | Patch available | CNA |
| — | net-imap (RubyGems) | 0.6.0 to before 0.6.4 | 0.6.4 | Patch available | GHSA-75xq-5h9v-w6px |
| — | net-imap (RubyGems) | 0.5.0 to before 0.5.14 | 0.5.14 | Patch available | GHSA-75xq-5h9v-w6px |
| — | net-imap (RubyGems) | before 0.4.24 | 0.4.24 | Patch available | GHSA-75xq-5h9v-w6px |
- 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-75xq-5h9v-w6px
- net-imap (RubyGems) Vendor— Affected 0.5.0 to before 0.5.14 Fixed in 0.5.14 Patch available GHSA-75xq-5h9v-w6px
- net-imap (RubyGems) Vendor— Affected before 0.4.24 Fixed in 0.4.24 Patch available GHSA-75xq-5h9v-w6px
Remediation
- Fix · CNA net-imap (ruby) Fixed in 0.4.24, 0.5.14, 0.6.4
- Fix · GHSA-75xq-5h9v-w6px net-imap (RubyGems) Fixed in 0.6.4 Advisory →
- Fix · GHSA-75xq-5h9v-w6px net-imap (RubyGems) Fixed in 0.5.14 Advisory →
- Fix · GHSA-75xq-5h9v-w6px net-imap (RubyGems) Fixed in 0.4.24 Advisory →
Red Hat 20 advisories
- RHSA-2026:40380 Released 2026-07-15 · Red Hat rating ImportantRed 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 ImportantRed 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-2026:37397 Released 2026-07-09 · Red Hat rating Importantruby security update
- Red Hat Enterprise Linux Server (v. 7 ELS) ruby-2.0.0.648-39.el7_9.1, ruby-irb-2.0.0.648-39.el7_9.1, ruby-libs-2.0.0.648-39.el7_9.1 +7
- Red Hat Enterprise Linux Server Optional (v. 7 ELS) ruby-devel-2.0.0.648-39.el7_9.1, ruby-doc-2.0.0.648-39.el7_9.1, ruby-tcltk-2.0.0.648-39.el7_9.1 +3
Show 17 more Red Hat advisories
- RHSA-2026:37238 Released 2026-07-09 · Red Hat rating Importantruby:3.3 security update
- Red Hat Enterprise Linux AppStream EUS (v.9.6) ruby-3.3.10-6.module+el9.6.0+24475+76cce029.aarch64::ruby:3.3, ruby-3.3.10-6.module+el9.6.0+24475+76cce029.i686::ruby:3.3, ruby-3.3.10-6.module+el9.6.0+24475+76cce029.ppc64le::ruby:3.3 +47
- RHSA-2026:36978 Released 2026-07-09 · Red Hat rating ImportantRed 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
- RHSA-2026:36099 Released 2026-07-07 · Red Hat rating Importantruby:3.3 security update
- Red Hat Enterprise Linux AppStream E4S (v.9.4) ruby-3.3.10-7.module+el9.4.0+24474+8fc4d0bd.aarch64::ruby:3.3, ruby-3.3.10-7.module+el9.4.0+24474+8fc4d0bd.i686::ruby:3.3, ruby-3.3.10-7.module+el9.4.0+24474+8fc4d0bd.ppc64le::ruby:3.3 +47
- RHSA-2026:35895 Released 2026-07-06 · Red Hat rating Importantruby security update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) ruby-3.3.10-11.el10_0.2, ruby-bundled-gems-3.3.10-11.el10_0.2, ruby-default-gems-3.3.10-11.el10_0.2 +20
- Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) ruby-doc-3.3.10-11.el10_0.2
- RHSA-2026:35867 Released 2026-07-06 · Red Hat rating Importantruby:2.5 security update
- Red Hat Enterprise Linux AppStream AUS (v.8.6) ruby-2.5.9-112.module+el8.6.0+24478+6e23d6ba.i686::ruby:2.5, ruby-2.5.9-112.module+el8.6.0+24478+6e23d6ba.src::ruby:2.5, ruby-2.5.9-112.module+el8.6.0+24478+6e23d6ba.x86_64::ruby:2.5 +44
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) ruby-2.5.9-112.module+el8.6.0+24478+6e23d6ba.i686::ruby:2.5, ruby-2.5.9-112.module+el8.6.0+24478+6e23d6ba.src::ruby:2.5, ruby-2.5.9-112.module+el8.6.0+24478+6e23d6ba.x86_64::ruby:2.5 +44
- RHSA-2026:35866 Released 2026-07-06 · Red Hat rating Importantruby:2.5 security update
- Red Hat Enterprise Linux AppStream AUS (v.8.4) ruby-2.5.9-109.module+el8.4.0+24479+aaeed2c5.i686::ruby:2.5, ruby-2.5.9-109.module+el8.4.0+24479+aaeed2c5.src::ruby:2.5, ruby-2.5.9-109.module+el8.4.0+24479+aaeed2c5.x86_64::ruby:2.5 +44
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) ruby-2.5.9-109.module+el8.4.0+24479+aaeed2c5.i686::ruby:2.5, ruby-2.5.9-109.module+el8.4.0+24479+aaeed2c5.src::ruby:2.5, ruby-2.5.9-109.module+el8.4.0+24479+aaeed2c5.x86_64::ruby:2.5 +44
- RHSA-2026:35834 Released 2026-07-06 · Red Hat rating Importantruby security update
- Red Hat Enterprise Linux AppStream E4S (v.9.2) ruby-3.0.4-161.el9_2.3, ruby-default-gems-3.0.4-161.el9_2.3, ruby-devel-3.0.4-161.el9_2.3 +18
- RHSA-2026:34076 Released 2026-07-01 · Red Hat rating Importantruby:2.5 security update
- Red Hat Enterprise Linux AppStream E4S (v.8.8) ruby-2.5.9-112.module+el8.8.0+24452+e70e99ef.i686::ruby:2.5, ruby-2.5.9-112.module+el8.8.0+24452+e70e99ef.ppc64le::ruby:2.5, ruby-2.5.9-112.module+el8.8.0+24452+e70e99ef.src::ruby:2.5 +47
- Red Hat Enterprise Linux AppStream TUS (v.8.8) ruby-2.5.9-112.module+el8.8.0+24452+e70e99ef.i686::ruby:2.5, ruby-2.5.9-112.module+el8.8.0+24452+e70e99ef.src::ruby:2.5, ruby-2.5.9-112.module+el8.8.0+24452+e70e99ef.x86_64::ruby:2.5 +44
- RHSA-2026:33577 Released 2026-06-30 · Red Hat rating Importantruby:4.0 security update
- Red Hat Enterprise Linux AppStream (v. 9) ruby-4.0.3-33.module+el9.8.0+24428+77f1d00a.aarch64::ruby:4.0, ruby-4.0.3-33.module+el9.8.0+24428+77f1d00a.i686::ruby:4.0, ruby-4.0.3-33.module+el9.8.0+24428+77f1d00a.ppc64le::ruby:4.0 +47
- RHSA-2026:33576 Released 2026-06-30 · Red Hat rating Importantruby:3.3 security update
- Red Hat Enterprise Linux AppStream (v. 9) ruby-3.3.10-7.module+el9.8.0+24406+8975e57f.aarch64::ruby:3.3, ruby-3.3.10-7.module+el9.8.0+24406+8975e57f.i686::ruby:3.3, ruby-3.3.10-7.module+el9.8.0+24406+8975e57f.ppc64le::ruby:3.3 +47
- RHSA-2026:33630 Released 2026-06-30 · Red Hat rating Importantruby security update
- Red Hat Enterprise Linux AppStream E4S (v.9.4) ruby-3.0.7-162.el9_4.3, ruby-default-gems-3.0.7-162.el9_4.3, ruby-devel-3.0.7-162.el9_4.3 +18
- RHSA-2026:33515 Released 2026-06-30 · Red Hat rating Importantruby:3.3 security update
- Red Hat Enterprise Linux AppStream (v. 8) ruby-3.3.10-7.module+el8.10.0+24407+4a33a056.aarch64::ruby:3.3, ruby-3.3.10-7.module+el8.10.0+24407+4a33a056.i686::ruby:3.3, ruby-3.3.10-7.module+el8.10.0+24407+4a33a056.ppc64le::ruby:3.3 +47
- RHSA-2026:33565 Released 2026-06-30 · Red Hat rating Importantruby security update
- Red Hat Enterprise Linux AppStream (v. 10) ruby-3.3.10-13.el10_2, ruby-bundled-gems-3.3.10-13.el10_2, ruby-default-gems-3.3.10-13.el10_2 +20
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) ruby-doc-3.3.10-13.el10_2
- RHSA-2026:33512 Released 2026-06-30 · Red Hat rating Importantruby security update
- Red Hat Enterprise Linux AppStream (v. 9) ruby-3.0.7-167.el9_8, ruby-default-gems-3.0.7-167.el9_8, ruby-devel-3.0.7-167.el9_8 +18
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) ruby-doc-3.0.7-167.el9_8
- RHSA-2026:33514 Released 2026-06-30 · Red Hat rating Importantruby:2.5 security update
- Red Hat Enterprise Linux AppStream (v. 8) ruby-2.5.9-115.module+el8.10.0+24408+7ffaaa88.aarch64::ruby:2.5, ruby-2.5.9-115.module+el8.10.0+24408+7ffaaa88.i686::ruby:2.5, ruby-2.5.9-115.module+el8.10.0+24408+7ffaaa88.ppc64le::ruby:2.5 +47
- RHSA-2026:33540 Released 2026-06-30 · Red Hat rating Importantruby4.0 security update
- Red Hat Enterprise Linux AppStream (v. 10) ruby4.0-4.0.3-35.el10_2, ruby4.0-devel-4.0.3-35.el10_2, ruby4.0-rubygem-mysql2-0.5.7-35.el10_2 +1
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) ruby4.0-doc-4.0.3-35.el10_2
- RHSA-2026:33462 Released 2026-06-30 · Red Hat rating Importantruby security update
- Red Hat CodeReady Linux Builder EUS (v.9.6) ruby-doc-3.0.7-165.el9_6.1
- Red Hat Enterprise Linux AppStream EUS (v.9.6) ruby-3.0.7-165.el9_6.1, ruby-default-gems-3.0.7-165.el9_6.1, ruby-devel-3.0.7-165.el9_6.1 +18
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat OpenShift AI (RHOAI) | Affected | No fix planned: Will not fix |
| Red Hat CodeReady Linux Builder EUS (v.9.6) | Fixed | RHSA-2026:33462 |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:33540, RHSA-2026:33565 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:33514, RHSA-2026:33515 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:33512, RHSA-2026:33576, RHSA-2026:33577 |
| Red Hat Enterprise Linux AppStream AUS (v.8.4) | Fixed | RHSA-2026:35866 |
| Red Hat Enterprise Linux AppStream AUS (v.8.6) | Fixed | RHSA-2026:35867 |
| Red Hat Enterprise Linux AppStream E4S (v.8.8) | Fixed | RHSA-2026:34076 |
| Red Hat Enterprise Linux AppStream E4S (v.9.2) | Fixed | RHSA-2026:35834 |
| Red Hat Enterprise Linux AppStream E4S (v.9.4) | Fixed | RHSA-2026:33630, RHSA-2026:36099 |
| Red Hat Enterprise Linux AppStream EUS (v. 10.0) | Fixed | RHSA-2026:35895 |
| Red Hat Enterprise Linux AppStream EUS (v.9.6) | Fixed | RHSA-2026:33462, RHSA-2026:37238 |
| Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) | Fixed | RHSA-2026:35866 |
| Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) | Fixed | RHSA-2026:35867 |
| Red Hat Enterprise Linux AppStream TUS (v.8.8) | Fixed | RHSA-2026:34076 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:33540, RHSA-2026:33565 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:33512 |
| Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) | Fixed | RHSA-2026:35895 |
| Red Hat Enterprise Linux Server (v. 7 ELS) | Fixed | RHSA-2026:37397 |
| Red Hat Enterprise Linux Server Optional (v. 7 ELS) | Fixed | RHSA-2026:37397 |
| Red Hat Hardened Images | Fixed | RHSA-2026:36978, RHSA-2026:38694, RHSA-2026:40380 |
Not affected: 6 products
- Red Hat 3scale API Management Platform 2
- Red Hat Enterprise Linux 6
- Red Hat Hardened Images
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
- Red Hat OpenShift Dev Spaces
Timeline
- 2026-10-02 Threatist record created from CVE-2026-42258
- 2026-10-03 Alias added: GHSA-75xq-5h9v-w6px
- 2026-11-05 Affected versions changed · Red Hat
References
Advisory 2
Other 33
- https://github.com/ruby/net-imap/releases/tag/v0.4.24
- https://github.com/ruby/net-imap/releases/tag/v0.5.14
- https://github.com/ruby/net-imap/releases/tag/v0.6.4
- https://github.com/ruby/net-imap/commit/aec06996eb87a7e1bbcef1f9f8926e8add2b8c71
- https://github.com/ruby/net-imap/commit/9db3e9d60bfb8f3735ea95015bf8a700f4af9cbb
- https://github.com/ruby/net-imap/commit/6bf02aef7e0b5931010c36e377f79a71636b306b
- https://access.redhat.com/errata/RHSA-2026:33462
- https://access.redhat.com/errata/RHSA-2026:37238
- https://access.redhat.com/errata/RHSA-2026:37397
- https://access.redhat.com/errata/RHSA-2026:38694
- https://access.redhat.com/errata/RHSA-2026:40380
- https://access.redhat.com/security/cve/CVE-2026-42258
- https://bugzilla.redhat.com/show_bug.cgi?id=2468498
- https://github.com/ruby/net-imap
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/net-imap/CVE-2026-42258.yml
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42258.json
- https://access.redhat.com/errata/RHSA-2026:33512
- https://access.redhat.com/errata/RHSA-2026:33514
- https://access.redhat.com/errata/RHSA-2026:33515
- https://access.redhat.com/errata/RHSA-2026:33540
- https://access.redhat.com/errata/RHSA-2026:33565
- https://access.redhat.com/errata/RHSA-2026:33576
- https://access.redhat.com/errata/RHSA-2026:33577
- https://access.redhat.com/errata/RHSA-2026:33630
- https://access.redhat.com/errata/RHSA-2026:33721
- https://access.redhat.com/errata/RHSA-2026:34076
- https://access.redhat.com/errata/RHSA-2026:35447
- https://access.redhat.com/errata/RHSA-2026:35834
- https://access.redhat.com/errata/RHSA-2026:35866
- https://access.redhat.com/errata/RHSA-2026:35867
- https://access.redhat.com/errata/RHSA-2026:35895
- https://access.redhat.com/errata/RHSA-2026:36099
- https://access.redhat.com/errata/RHSA-2026:36978
More ruby Net vulnerabilities
- TI-2026-30563 net-imap vulnerable to STARTTLS stripping via invalid response timing CVSS 4.0HIGH 7.6
- 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-2026-30573 net-imap: Command Injection via "raw" arguments to multiple commands CVSS 4.0MEDIUM 5.8
- TI-2026-30562 net-imap: Quadratic complexity when reading response literals CVSS 4.0LOW 2.3
Sources
- CVE-2026-42258 · CVE Program
- CVE-2026-42258 · NVD
- FIRST EPSS
- GHSA-75xq-5h9v-w6px · GitHub Advisory Database · CC BY 4.0
- CVE-2026-42258 · Red Hat security data · CC BY 4.0
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