FKIE_CVE-2026-42246

Vulnerability from fkie_nvd - Published: 2026-05-09 20:16 - Updated: 2026-07-02 12:17
Severity
7.4 (High) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
7.4 (High) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Summary
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.
References
security-advisories@github.comhttps://github.com/ruby/net-imap/commit/0ede4c40b1523dfeaf95777b2678e54cc0fd9618Patch
security-advisories@github.comhttps://github.com/ruby/net-imap/commit/24a4e770b43230286a05aa2a9746cdbb3eb8485ePatch
security-advisories@github.comhttps://github.com/ruby/net-imap/commit/97e2488fb5401a1783bddd959dde007d9fbce42cPatch
security-advisories@github.comhttps://github.com/ruby/net-imap/commit/f79d35bf5833f186e81044c57c843eda30c873daPatch
security-advisories@github.comhttps://github.com/ruby/net-imap/releases/tag/v0.3.10Release Notes
security-advisories@github.comhttps://github.com/ruby/net-imap/releases/tag/v0.4.24Release Notes
security-advisories@github.comhttps://github.com/ruby/net-imap/releases/tag/v0.5.14Release Notes
security-advisories@github.comhttps://github.com/ruby/net-imap/security/advisories/GHSA-vcgp-9326-pqcpMitigation, Vendor Advisory
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:33462
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:33512
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:33514
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:33515
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:33540
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:33551
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:33552
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:33565
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:33576
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:33577
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:33630
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:33721
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:34076
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/security/cve/CVE-2026-42246
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://bugzilla.redhat.com/show_bug.cgi?id=2468499
0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42246.json
Impacted products
Vendor Product Version
ruby-lang net\ \
ruby-lang net\ \
ruby-lang net\ \
ruby-lang net\ \
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "net-imap",
          "vendor": "ruby",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.3.10"
            },
            {
              "status": "affected",
              "version": "\u003e= 0.4.0, \u003c 0.4.24"
            },
            {
              "status": "affected",
              "version": "\u003e= 0.5.0, \u003c 0.5.14"
            },
            {
              "status": "affected",
              "version": "\u003e= 0.6.0, \u003c 0.6.4"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    },
    {
      "affectedData": [
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:10.2"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux AppStream (v. 10)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/a:redhat:enterprise_linux:8::appstream"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux AppStream (v. 8)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/a:redhat:rhel_e4s:8.8::appstream"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux AppStream E4S (v.8.8)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/a:redhat:rhel_tus:8.8::appstream"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux AppStream TUS (v.8.8)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/a:redhat:rhel_e4s:9.4::appstream"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux AppStream E4S (v.9.4)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/a:redhat:rhel_eus:9.6::appstream"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux AppStream EUS (v.9.6)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/a:redhat:enterprise_linux:9::appstream"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux AppStream (v. 9)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:10.2"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/a:redhat:rhel_eus:9.6::crb"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat CodeReady Linux Builder EUS (v.9.6)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/a:redhat:enterprise_linux:9::crb"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/a:redhat:hummingbird:1"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Hardened Images",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:6"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux 6",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:7"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat Enterprise Linux 7",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/a:redhat:openshift:4"
          ],
          "defaultStatus": "affected",
          "product": "Red Hat OpenShift Container Platform 4",
          "vendor": "Red Hat"
        },
        {
          "cpes": [
            "cpe:/a:redhat:red_hat_3scale_amp:2"
          ],
          "defaultStatus": "unaffected",
          "product": "Red Hat 3scale API Management Platform 2",
          "vendor": "Red Hat"
        }
      ],
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:ruby-lang:net\\:\\:imap:*:*:*:*:*:ruby:*:*",
              "matchCriteriaId": "E2B6117A-DE77-4BB9-A73C-F20933514BAB",
              "versionEndExcluding": "0.3.10",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:ruby-lang:net\\:\\:imap:*:*:*:*:*:ruby:*:*",
              "matchCriteriaId": "79EE9345-B825-40F9-9CFF-9E9E1A3783DD",
              "versionEndExcluding": "0.4.24",
              "versionStartIncluding": "0.4.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:ruby-lang:net\\:\\:imap:*:*:*:*:*:ruby:*:*",
              "matchCriteriaId": "2CCEB891-1D8F-4431-A79C-2A7560A84F4E",
              "versionEndExcluding": "0.5.14",
              "versionStartIncluding": "0.5.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:ruby-lang:net\\:\\:imap:*:*:*:*:*:ruby:*:*",
              "matchCriteriaId": "9A6D1995-BFA3-490F-967D-252CA7BE2264",
              "versionEndExcluding": "0.6.4",
              "versionStartIncluding": "0.6.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "id": "CVE-2026-42246",
  "lastModified": "2026-07-02T12:17:15.963",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 7.4,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
          "version": "3.1"
        },
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        "impactScore": 5.2,
        "source": "nvd@nist.gov",
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      },
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          "availabilityImpact": "NONE",
          "baseScore": 7.4,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
          "version": "3.1"
        },
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        "impactScore": 5.2,
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "type": "Secondary"
      }
    ],
    "cvssMetricV40": [
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        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 7.6,
          "baseSeverity": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "PASSIVE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
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          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
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          "role": "CISA Coordinator",
          "timestamp": "2026-05-12T02:29:05.120225Z",
          "version": "2.0.3"
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  "published": "2026-05-09T20:16:28.163",
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  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
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          "value": "CWE-392"
        },
        {
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          "value": "CWE-393"
        },
        {
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          "value": "CWE-636"
        },
        {
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          "value": "CWE-754"
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          "value": "CWE-841"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
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    {
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          "lang": "en",
          "value": "CWE-325"
        }
      ],
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "type": "Secondary"
    }
  ]
}


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Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.