CVE-2026-42258

MEDIUMNVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under NVD CVSS v3. EPSS exploit probability: 0.8%, top 46% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1.3%CVSS: 5.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
5.3
EG Score
5.3MEDIUMmedium confidence
EG Risk
24
EG Risk 24/100

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity53% × 45%
Exploitation1% × 40%
Automatability0% × 15%
EPSS PROB
1.3%
EPSS %ILE
68th
KEV
Not listed

Published

May 9, 2026

Last Modified

September 1, 2026

Advisory Details (4)

Auto-updated Jun 21, 2026
Patch available. Sources: github_release, github.
githubMentions a patch (unverified)

Command Injection via unvalidated Symbol inputs · Advisory · ruby/net-imap · GitHub

https://github.com/ruby/net-imap/security/advisories/GHSA-75xq-5h9v-w6px
github_release Patch Available

v0.6.4

Patch available: ruby/net-imap v0.6.4

https://github.com/ruby/net-imap/releases/tag/v0.6.4
github_release Patch Available

v0.5.14

Patch available: ruby/net-imap v0.5.14

https://github.com/ruby/net-imap/releases/tag/v0.5.14
github_release Patch Available

v0.4.24

Patch available: ruby/net-imap v0.4.24

https://github.com/ruby/net-imap/releases/tag/v0.4.24

Vendor Advisories for CVE-2026-42258(20)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(21)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubunturuby2.3-tcltk (2.3.1-2~ubuntu16.04.16+esm15) @ xenial2026-08-24ubuntu
redhatruby3-3-main-3.3.10-23.4.hum12026-07-15redhat
redhatruby3-4-main-3.4.10-31.hum12026-07-13redhat
redhatruby4-0-main-4.0.5-35.hum12026-07-09redhat
redhatruby:3.3-9060020260630075016.92026-07-09redhat
redhatruby-0:2.0.0.648-39.el7_9.12026-07-09redhat
redhatruby:3.3-9040020260630065449.92026-07-07redhat
redhatruby-0:3.0.4-161.el9_2.32026-07-06redhat
redhatruby:2.5-8040020260630124058.522a0ee42026-07-06redhat
redhatruby:2.5-8060020260630123825.ad008a3a2026-07-06redhat
redhatruby-0:3.3.10-11.el10_0.22026-07-06redhat
redhatruby:2.5-8080020260625114827.63b345852026-07-01redhat
redhatruby-0:3.0.7-165.el9_6.12026-06-30redhat
redhatruby:3.3-9080020260615131001.92026-06-30redhat
redhatruby:4.0-9080020260619130154.92026-06-30redhat
redhatruby-0:3.3.10-13.el10_22026-06-30redhat
redhatruby-0:3.0.7-167.el9_82026-06-30redhat
redhatruby4.0-0:4.0.3-35.el10_22026-06-30redhat
redhatruby-0:3.0.7-162.el9_4.32026-06-30redhat
redhatruby:2.5-8100020260615131019.489197e62026-06-30redhat
redhatruby:3.3-8100020260615131010.489197e62026-06-30redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
ruby2.72.7.4-1 ... 2.7.5-1 (8 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
ruby3.13.1.2-7 ... 3.1.2-8.5 (8 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
ruby3.33.3.8-2, 3.3.8-2.1, 3.3.8-2.2
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
ruby3.33.3.8-2, 3.3.8-2.1, 3.3.8-2.2
  • every version on: no fix on record
—
RubyGems(1)
PackageVulnerable rangeFix by version rangeDependents
net-imap0.1.0 ... 0.4.9.1 (45 versions)
  • 0.6.0 up to 0.6.4: fixed in 0.6.4
  • 0.5.0 up to 0.5.14: fixed in 0.5.14
  • every version up to 0.4.24: fixed in 0.4.24
—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(2)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 8× in last 7d / 24× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 208 total refreshes for this CVE.

  1. 2026-10-10 01:03 UTCOSV refresh
  2. 2026-10-09 20:07 UTCEPSS rescore
  3. 2026-10-08 17:12 UTCEPSS rescore
  4. 2026-10-07 23:48 UTCEPSS rescore
  5. 2026-10-06 15:17 UTCEPSS rescore
  6. 2026-10-05 17:43 UTCEPSS rescore
  7. 2026-10-04 23:22 UTCEPSS rescore
  8. 2026-10-03 14:25 UTCEPSS rescore
  9. 2026-10-01 19:50 UTCEPSS rescore
  10. 2026-09-30 15:03 UTCEPSS rescore
  11. 2026-09-27 13:48 UTCEPSS rescore
  12. 2026-09-26 15:58 UTCEPSS rescore
  13. 2026-09-23 17:53 UTCEPSS rescore
  14. 2026-09-20 20:15 UTCEPSS rescore
  15. 2026-09-20 09:03 UTCOSV refresh
  16. 2026-09-18 19:28 UTCEPSS rescore
  17. 2026-09-17 19:31 UTCEPSS rescore
  18. 2026-09-16 14:08 UTCEPSS rescore
  19. 2026-09-16 05:15 UTCEPSS rescore
  20. 2026-09-13 16:47 UTCEPSS rescore
  21. 2026-09-12 15:01 UTCEPSS rescore
  22. 2026-09-11 14:53 UTCEPSS rescore
  23. 2026-09-11 09:37 UTCEPSS rescore
  24. 2026-09-10 09:34 UTCEPSS rescore
  25. 2026-09-08 22:00 UTCEPSS rescore
Show 75 more
  1. 2026-09-07 16:01 UTCEPSS rescore
  2. 2026-09-06 13:47 UTCEPSS rescore
  3. 2026-09-04 05:06 UTCEPSS rescore
  4. 2026-09-02 14:12 UTCEPSS rescore
  5. 2026-09-01 13:54 UTCEPSS rescore
  6. 2026-09-01 12:22 UTCEG score recompute
  7. 2026-09-01 12:22 UTCVendor advisory
  8. 2026-08-30 19:17 UTCEPSS rescore
  9. 2026-08-30 01:22 UTCEPSS rescore
  10. 2026-08-28 21:41 UTCEPSS rescore
  11. 2026-08-27 14:25 UTCEPSS rescore
  12. 2026-08-26 14:46 UTCEPSS rescore
  13. 2026-08-25 13:49 UTCEPSS rescore
  14. 2026-08-24 13:30 UTCVendor advisory
  15. 2026-08-24 12:26 UTCEG score recompute
  16. 2026-08-24 12:26 UTCVendor advisory
  17. 2026-08-23 18:50 UTCEG score recompute
  18. 2026-08-23 18:50 UTCVendor advisory
  19. 2026-08-23 00:19 UTCEPSS rescore
  20. 2026-08-21 23:49 UTCEPSS rescore
  21. 2026-08-20 22:55 UTCEPSS rescore
  22. 2026-08-20 12:43 UTCEG score recompute
  23. 2026-08-20 12:43 UTCVendor advisory
  24. 2026-08-19 17:03 UTCEPSS rescore
  25. 2026-08-18 13:48 UTCEPSS rescore
  26. 2026-08-17 13:47 UTCEPSS rescore
  27. 2026-08-17 11:26 UTCEG score recompute
  28. 2026-08-17 11:26 UTCVendor advisory
  29. 2026-08-16 14:56 UTCEPSS rescore
  30. 2026-08-16 04:30 UTCEG score recompute
  31. 2026-08-16 04:30 UTCVendor advisory
  32. 2026-08-16 02:14 UTCEPSS rescore
  33. 2026-08-15 01:30 UTCEPSS rescore
  34. 2026-08-15 00:50 UTCVendor advisory
  35. 2026-08-14 03:05 UTCEG score recompute
  36. 2026-08-14 03:05 UTCVendor advisory
  37. 2026-08-13 22:00 UTCEPSS rescore
  38. 2026-08-12 20:43 UTCEG score recompute
  39. 2026-08-12 20:43 UTCVendor advisory
  40. 2026-08-12 13:51 UTCEPSS rescore
  41. 2026-08-11 22:58 UTCEG score recompute
  42. 2026-08-11 22:58 UTCVendor advisory
  43. 2026-08-11 13:43 UTCEPSS rescore
  44. 2026-08-11 01:14 UTCEG score recompute
  45. 2026-08-11 01:14 UTCVendor advisory
  46. 2026-08-11 00:00 UTCEPSS rescore
  47. 2026-08-10 03:12 UTCEG score recompute
  48. 2026-08-10 03:12 UTCVendor advisory
  49. 2026-08-09 13:46 UTCEPSS rescore
  50. 2026-08-09 05:27 UTCEG score recompute
  51. 2026-08-09 05:27 UTCVendor advisory
  52. 2026-08-08 16:37 UTCEPSS rescore
  53. 2026-08-08 07:42 UTCEG score recompute
  54. 2026-08-08 07:42 UTCVendor advisory
  55. 2026-08-07 09:57 UTCEG score recompute
  56. 2026-08-07 09:57 UTCVendor advisory
  57. 2026-08-06 13:46 UTCEPSS rescore
  58. 2026-08-06 11:29 UTCEG score recompute
  59. 2026-08-06 11:29 UTCVendor advisory
  60. 2026-08-05 19:17 UTCEPSS rescore
  61. 2026-08-05 13:44 UTCVendor advisory
  62. 2026-08-05 12:33 UTCEG score recompute
  63. 2026-08-05 12:33 UTCVendor advisory
  64. 2026-08-04 15:10 UTCEPSS rescore
  65. 2026-08-04 10:38 UTCEPSS rescore
  66. 2026-08-03 22:24 UTCEG score recompute
  67. 2026-08-03 22:24 UTCVendor advisory
  68. 2026-08-03 10:36 UTCEPSS rescore
  69. 2026-08-03 00:39 UTCVendor advisory
  70. 2026-08-02 02:37 UTCEG score recompute
  71. 2026-08-02 02:37 UTCVendor advisory
  72. 2026-08-02 02:27 UTCEPSS rescore
  73. 2026-08-01 04:16 UTCEPSS rescore
  74. 2026-07-30 16:28 UTCEPSS rescore
  75. 2026-07-30 01:30 UTCEPSS rescore

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-42258?
CVE-2026-42258 is a medium vulnerability published on May 9, 2026. 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…
When was CVE-2026-42258 disclosed?
CVE-2026-42258 was first published on May 9, 2026, with the most recent update on September 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42258 actively exploited?
CVE-2026-42258 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.3% probability of exploitation in the next 30 days (68th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-42258?
CVE-2026-42258 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-42258?
A fix for CVE-2026-42258 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-42258 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-42258

Explore →

Is Your Infrastructure Affected by CVE-2026-42258?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs