CVE-2026-42246

HIGHNVD 7.47.4
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

This high-severity CVE scores 7.4 under NVD CVSS v3. EPSS exploit probability: 0.3% (24th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3

Also known asEUVD-2026-28924 (ENISA EUVD) · GHSA-vcgp-9326-pqcp (GitHub Security Advisories)Source: ENISA EUVD

7.4EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 7.4Exploit: 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 0.3.10, 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.

CVSS v3
7.4
EG Score
7.4HIGHmedium confidence
EG Risk
33
EG Risk 33/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity74% × 45%
Impact severity (EG Severity): CVSS 7.4 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.3% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.3%
EPSS %ILE
24th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.4): severity, escalated by confirmed exploitation. This CVE's 7.4 is its impact severity (EG Severity), not escalated.

EG Severity
7.4 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-07). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

May 9, 2026

Last Modified

August 24, 2026

Advisory Details (8)

Auto-updated May 18, 2026
Patch available. Sources: github.
GitHub advisoryMentions a patch (unverified)

STARTTLS stripping via invalid response timing · Advisory · ruby/net-imap · GitHub

https://github.com/ruby/net-imap/security/advisories/GHSA-vcgp-9326-pqcp
Web page

Release v0.5.14 · ruby/net-imap · GitHub

https://github.com/ruby/net-imap/releases/tag/v0.5.14
Web page

Release v0.4.24 · ruby/net-imap · GitHub

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

Release v0.3.10 · ruby/net-imap · GitHub

https://github.com/ruby/net-imap/releases/tag/v0.3.10
Web page

🔀 Merge pull request #665 from ruby/backport/v0.5/STARTTLS-stripping · ruby/net-imap@f79d35b · GitHub

https://github.com/ruby/net-imap/commit/f79d35bf5833f186e81044c57c843eda30c873da
Web page

🔀 Merge pull request #667 from ruby/backport/v0.3/STARTTLS-stripping · ruby/net-imap@97e2488 · GitHub

https://github.com/ruby/net-imap/commit/97e2488fb5401a1783bddd959dde007d9fbce42c
Web page

🔀 Merge pull request #666 from ruby/backport/v0.4/STARTTLS-stripping · ruby/net-imap@24a4e77 · GitHub

https://github.com/ruby/net-imap/commit/24a4e770b43230286a05aa2a9746cdbb3eb8485e
Web page

🔀 Merge pull request #664 from ruby/security/STARTTLS-stripping · ruby/net-imap@0ede4c4 · GitHub

https://github.com/ruby/net-imap/commit/0ede4c40b1523dfeaf95777b2678e54cc0fd9618

Vendor Advisories for CVE-2026-42246(20)

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

Patch Availability(27)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubunturuby3.3-doc (3.3.8-2ubuntu3.1) @ resolute2026-11-01ubuntu
ubunturuby2.3-tcltk (2.3.1-2~ubuntu16.04.16+esm14) @ xenial2026-11-01ubuntu
redhatruby3-4-main-0.3.1-31.hum12026-07-13redhat
redhatruby-0:2.0.0.648-39.el7_9.12026-07-09redhat
redhatruby:3.3-9060020260630075016.92026-07-09redhat
redhatruby:3.3-9040020260630065449.92026-07-07redhat
redhatruby-0:3.0.4-161.el9_2.32026-07-06redhat
redhatruby:2.5-8060020260630123825.ad008a3a2026-07-06redhat
redhatruby:2.5-8040020260630124058.522a0ee42026-07-06redhat
redhatruby-0:3.3.10-11.el10_0.22026-07-06redhat
redhatruby:2.5-8080020260625114827.63b345852026-07-01redhat
redhatruby3-3-main-3.3.10-23.2.hum12026-06-30redhat
redhatruby-0:3.0.7-162.el9_4.32026-06-30redhat
redhatruby:2.5-8100020260615131019.489197e62026-06-30redhat
redhatruby-0:3.3.10-13.el10_22026-06-30redhat
redhatruby:3.3-8100020260615131010.489197e62026-06-30redhat
redhatruby4-0-main-4.0.0-33.4.hum12026-06-30redhat
redhatruby:3.3-9080020260615131001.92026-06-30redhat
redhatruby:4.0-9080020260619130154.92026-06-30redhat
redhatruby4.0-0:4.0.3-35.el10_22026-06-30redhat
redhatruby-0:3.0.7-167.el9_82026-06-30redhat
redhatruby-0:3.0.7-165.el9_6.12026-06-30redhat
redhatruby3-4-main-3.4.8-31.2.hum12026-06-30redhat
rubygemsnet-imap @ 0.6.4 (fixes >= 0.6.0, <= 0.6.3)—ghsa
rubygemsnet-imap @ 0.5.14 (fixes >= 0.5.0, <= 0.5.13)—ghsa
rubygemsnet-imap @ 0.3.10 (fixes >= 0, <= 0.3.9)—ghsa
rubygemsnet-imap @ 0.4.24 (fixes >= 0.4.0, <= 0.4.23)—ghsa

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

(6 across 6 ecosystems)
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
ruby-net-imap—
  • every version up to 0.4.25-r0: fixed in 0.4.25-r0
—
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 up to 3.3.13-0+deb13u1: fixed in 3.3.13-0+deb13u1
—
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 ... 0.3.9 (19 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
  • 0.4.0 up to 0.4.24: fixed in 0.4.24
  • every version up to 0.3.10: fixed in 0.3.10
—

Weakness Classification(6)

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

Additional Vendor Advisories

(3)

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 9× in last 7d / 36× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 252 rows on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 152 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-12 16:33 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  2. 2026-11-11 16:39 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  3. 2026-11-10 16:44 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  4. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  5. 2026-11-08 16:39 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  6. 2026-11-08 11:44 UTCEchelonGraph re-scored
  7. 2026-11-08 11:44 UTCVendor advisory
  8. 2026-11-08 11:44 UTCGHSA enrichmentGHSA-vcgp-9326-pqcp · GitHub severity HIGH
  9. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  10. 2026-11-06 16:37 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  11. 2026-11-05 16:37 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  12. 2026-11-04 16:35 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  13. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  14. 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  15. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  16. 2026-11-01 07:50 UTCGHSA enrichmentGHSA-vcgp-9326-pqcp · GitHub severity HIGH
  17. 2026-11-01 04:38 UTCEchelonGraph re-scored
  18. 2026-11-01 04:38 UTCVendor advisory
  19. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  20. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  21. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  22. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  23. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  24. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  25. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
Show 75 more
  1. 2026-10-25 14:29 UTCEchelonGraph re-scored
  2. 2026-10-24 21:33 UTCEchelonGraph re-scored
  3. 2026-10-24 21:33 UTCVendor advisory
  4. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  5. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  6. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  7. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  8. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  9. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  10. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  11. 2026-10-18 03:41 UTCEchelonGraph re-scored
  12. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  13. 2026-10-17 14:28 UTCEchelonGraph re-scored
  14. 2026-10-17 14:28 UTCVendor advisory
  15. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  16. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  17. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  18. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  19. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  20. 2026-10-12 16:07 UTCEchelonGraph re-scored
  21. 2026-10-11 19:49 UTCEchelonGraph re-scored
  22. 2026-10-11 17:03 UTCEchelonGraph re-scored
  23. 2026-10-11 14:29 UTCEchelonGraph re-scored
  24. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  25. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  26. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  27. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  28. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  29. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  30. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  31. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  32. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  33. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  34. 2026-10-01 07:40 UTCOSV refresh
  35. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  36. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  37. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  38. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  39. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  40. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  41. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  42. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  43. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  44. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  45. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  46. 2026-09-12 08:23 UTCOSV refresh
  47. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  48. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  49. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  50. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  51. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  52. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  53. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  54. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  55. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  56. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  57. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  58. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  59. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  60. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  61. 2026-08-24 13:30 UTCVendor advisory
  62. 2026-08-24 12:26 UTCEchelonGraph re-scored
  63. 2026-08-24 12:26 UTCVendor advisory
  64. 2026-08-23 18:50 UTCEchelonGraph re-scored
  65. 2026-08-23 18:50 UTCVendor advisory
  66. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  67. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  68. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  69. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  70. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  71. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  72. 2026-08-17 11:27 UTCEchelonGraph re-scored
  73. 2026-08-17 11:27 UTCVendor advisory
  74. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  75. 2026-08-16 04:30 UTCEchelonGraph re-scored

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

Frequently asked(5)

What is CVE-2026-42246?
CVE-2026-42246 is a high-severity vulnerability; its CVE record was published on May 9, 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,…
When was the CVE record for CVE-2026-42246 published?
The CVE record for CVE-2026-42246 was published on May 9, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of August 24, 2026; the record at its source may have been updated since.
Is CVE-2026-42246 actively exploited?
CVE-2026-42246 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (24th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-42246?
CVE-2026-42246 has a CVSS v3 base score of 7.4 (NVD).
How do I remediate CVE-2026-42246?
A fix for CVE-2026-42246 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-42246 are linked in the Vendor Advisories panel on this page.

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