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 47% 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
Trending — 3 sources updated this week
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 5.3Exploit: None knownExposed: 0

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
5.3(medium)
EG Risk
24(Track)
EG Risk 24/100SSVC: Track

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%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
53%
KEV
Not listed

Published

May 9, 2026

Last Modified

August 24, 2026

Advisory Details (4)

Auto-updated Jun 21, 2026
Patch available. Sources: github_release, github.
github Patch Available

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 / EcosystemFixed in / 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 rangeFixed inDependents
ruby2.72.7.4-1 ... 2.7.5-1 (8 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
ruby3.13.1.2-7 ... 3.1.2-8.5 (8 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
ruby3.33.3.8-2, 3.3.8-2.1, 3.3.8-2.2——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
ruby3.33.3.8-2, 3.3.8-2.1, 3.3.8-2.2——
RubyGems(1)
PackageVulnerable rangeFixed inDependents
net-imap0.1.0 ... 0.4.9.1 (45 versions)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 12× in last 7d / 65× 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 171 total refreshes for this CVE.

  1. 2026-08-25 13:49 UTCEPSS rescore
  2. 2026-08-24 13:30 UTCVendor advisory
  3. 2026-08-24 12:26 UTCEG score recompute
  4. 2026-08-24 12:26 UTCVendor advisory
  5. 2026-08-23 18:50 UTCEG score recompute
  6. 2026-08-23 18:50 UTCVendor advisory
  7. 2026-08-23 00:19 UTCEPSS rescore
  8. 2026-08-21 23:49 UTCEPSS rescore
  9. 2026-08-20 22:55 UTCEPSS rescore
  10. 2026-08-20 12:43 UTCEG score recompute
  11. 2026-08-20 12:43 UTCVendor advisory
  12. 2026-08-19 17:03 UTCEPSS rescore
  13. 2026-08-18 13:48 UTCEPSS rescore
  14. 2026-08-17 13:47 UTCEPSS rescore
  15. 2026-08-17 11:26 UTCEG score recompute
  16. 2026-08-17 11:26 UTCVendor advisory
  17. 2026-08-16 14:56 UTCEPSS rescore
  18. 2026-08-16 04:30 UTCEG score recompute
  19. 2026-08-16 04:30 UTCVendor advisory
  20. 2026-08-16 02:14 UTCEPSS rescore
  21. 2026-08-15 01:30 UTCEPSS rescore
  22. 2026-08-15 00:50 UTCVendor advisory
  23. 2026-08-14 03:05 UTCEG score recompute
  24. 2026-08-14 03:05 UTCVendor advisory
  25. 2026-08-13 22:00 UTCEPSS rescore
Show 75 more
  1. 2026-08-12 20:43 UTCEG score recompute
  2. 2026-08-12 20:43 UTCVendor advisory
  3. 2026-08-12 13:51 UTCEPSS rescore
  4. 2026-08-11 22:58 UTCEG score recompute
  5. 2026-08-11 22:58 UTCVendor advisory
  6. 2026-08-11 13:43 UTCEPSS rescore
  7. 2026-08-11 01:14 UTCEG score recompute
  8. 2026-08-11 01:14 UTCVendor advisory
  9. 2026-08-11 00:00 UTCEPSS rescore
  10. 2026-08-10 03:12 UTCEG score recompute
  11. 2026-08-10 03:12 UTCVendor advisory
  12. 2026-08-09 13:46 UTCEPSS rescore
  13. 2026-08-09 05:27 UTCEG score recompute
  14. 2026-08-09 05:27 UTCVendor advisory
  15. 2026-08-08 16:37 UTCEPSS rescore
  16. 2026-08-08 07:42 UTCEG score recompute
  17. 2026-08-08 07:42 UTCVendor advisory
  18. 2026-08-07 09:57 UTCEG score recompute
  19. 2026-08-07 09:57 UTCVendor advisory
  20. 2026-08-06 13:46 UTCEPSS rescore
  21. 2026-08-06 11:29 UTCEG score recompute
  22. 2026-08-06 11:29 UTCVendor advisory
  23. 2026-08-05 19:17 UTCEPSS rescore
  24. 2026-08-05 13:44 UTCVendor advisory
  25. 2026-08-05 12:33 UTCEG score recompute
  26. 2026-08-05 12:33 UTCVendor advisory
  27. 2026-08-04 15:10 UTCEPSS rescore
  28. 2026-08-04 10:38 UTCEPSS rescore
  29. 2026-08-03 22:24 UTCEG score recompute
  30. 2026-08-03 22:24 UTCVendor advisory
  31. 2026-08-03 10:36 UTCEPSS rescore
  32. 2026-08-03 00:39 UTCVendor advisory
  33. 2026-08-02 02:37 UTCEG score recompute
  34. 2026-08-02 02:37 UTCVendor advisory
  35. 2026-08-02 02:27 UTCEPSS rescore
  36. 2026-08-01 04:16 UTCEPSS rescore
  37. 2026-07-30 16:28 UTCEPSS rescore
  38. 2026-07-30 01:30 UTCEPSS rescore
  39. 2026-07-28 15:36 UTCEPSS rescore
  40. 2026-07-27 14:13 UTCEPSS rescore
  41. 2026-07-26 14:54 UTCEPSS rescore
  42. 2026-07-26 14:54 UTCEPSS rescore
  43. 2026-07-26 08:25 UTCEG score recompute
  44. 2026-07-26 08:25 UTCVendor advisory
  45. 2026-07-25 14:18 UTCEPSS rescore
  46. 2026-07-24 14:17 UTCEPSS rescore
  47. 2026-07-23 14:18 UTCEPSS rescore
  48. 2026-07-23 03:11 UTCEG score recompute
  49. 2026-07-22 14:08 UTCEPSS rescore
  50. 2026-07-21 15:24 UTCEPSS rescore
  51. 2026-07-20 17:08 UTCEPSS rescore
  52. 2026-07-19 14:31 UTCEPSS rescore
  53. 2026-07-19 02:29 UTCEPSS rescore
  54. 2026-07-18 10:04 UTCEPSS rescore
  55. 2026-07-16 17:03 UTCEPSS rescore
  56. 2026-07-16 12:29 UTCNVD updateCVSS v3 → 5.3 · severity → MEDIUM
  57. 2026-07-16 12:08 UTCMITRE cvelistV5CVSS v3 → 7.1 · severity → HIGH
  58. 2026-07-16 03:53 UTCOSV refresh
  59. 2026-07-15 16:57 UTCEPSS rescore
  60. 2026-07-15 04:20 UTCNVD updateCVSS v3 → 5.3 · severity → MEDIUM
  61. 2026-07-15 03:14 UTCMITRE cvelistV5CVSS v3 → 7.1 · severity → HIGH
  62. 2026-07-15 02:25 UTCNVD updateCVSS v3 → 5.3 · severity → MEDIUM
  63. 2026-07-15 02:00 UTCEPSS rescore
  64. 2026-07-15 01:21 UTCMITRE cvelistV5CVSS v3 → 7.1 · severity → HIGH
  65. 2026-07-13 22:30 UTCEPSS rescore
  66. 2026-07-13 14:08 UTCNVD updateCVSS v3 → 5.3 · severity → MEDIUM
  67. 2026-07-13 12:52 UTCMITRE cvelistV5CVSS v3 → 7.1 · severity → HIGH
  68. 2026-07-12 05:46 UTCEPSS rescore
  69. 2026-07-11 08:27 UTCEPSS rescore
  70. 2026-07-10 12:26 UTCNVD updateCVSS v3 → 5.3 · severity → MEDIUM
  71. 2026-07-10 12:12 UTCMITRE cvelistV5CVSS v3 → 7.1 · severity → HIGH
  72. 2026-07-09 19:10 UTCEPSS rescore
  73. 2026-07-08 15:15 UTCEPSS rescore
  74. 2026-07-07 14:14 UTCNVD updateCVSS v3 → 5.3 · severity → MEDIUM
  75. 2026-07-07 13:46 UTCEPSS rescore

Related CVEs(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 in the National Vulnerability Database on May 9, 2026, with the most recent update on August 24, 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% probability of exploitation in the next 30 days, which ranks it in the top 46.7% of all 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?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42258, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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