CVE-2026-42246

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Source
https://cve.org/CVERecord?id=CVE-2026-42246
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42246.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-42246
Aliases
Downstream
BELL (1)
CGA (133)
CLEANSTART (3)
DEBIAN (1)
ECHO (1)
MINI (17)
OESA (1)
openSUSE (2)
RHSA (21)
RLSA (7)
SUSE (2)
UBUNTU (1)
Related
ALSA (7)
openSUSE (2)
SUSE (2)
Published
2026-05-09T19:33:17Z
Modified
2026-10-21T17:42:34Z
Severity
  • 7.6 (High) CVSS_V4 - 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 CVSS Calculator
Summary
net-imap vulnerable to STARTTLS stripping via invalid response timing
Details

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.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-392",
        "CWE-393",
        "CWE-636",
        "CWE-754",
        "CWE-841"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42246.json"
}
References

Affected packages

Git / github.com/ruby/net-imap

Affected ranges

Type
GIT
Repo
https://github.com/ruby/net-imap
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
ec89812d3c986d6394d3bc0b93048e704aec6af9
Introduced
a9459de2c725563d27943e73a92a61f69ef9b048
Fixed
24a4e770b43230286a05aa2a9746cdbb3eb8485e
Introduced
cc13c91c65b78ee33ebf4960d547173e761cafdc
Fixed
4063bc1d1d3e21046544ed7a2c131e5f886bab01
Introduced
567518cae5500f7c4776a1fd4e9bbd599e98b9bf
Fixed
3e490673dca65d0cfeeeb3fbf1fdaa188d6f27c4
Fixed
0ede4c40b1523dfeaf95777b2678e54cc0fd9618
Fixed
97e2488fb5401a1783bddd959dde007d9fbce42c
Fixed
f79d35bf5833f186e81044c57c843eda30c873da
Database specific
Show details 
{
    "extracted_events":  [
        {
            "cpe":  "cpe:2.3:a:ruby-lang:net\\:\\:imap:*:*:*:*:*:ruby:*:*",
            "range":  [
                {
                    "introduced":  "0"
                },
                {
                    "fixed":  "0.3.10"
                }
            ],
            "source":  "CPE_RANGE"
        },
        {
            "cpe":  "cpe:2.3:a:ruby-lang:net\\:\\:imap:*:*:*:*:*:ruby:*:*",
            "range":  [
                {
                    "introduced":  "0.4.0"
                },
                {
                    "fixed":  "0.4.24"
                }
            ],
            "source":  "CPE_RANGE"
        },
        {
            "cpe":  "cpe:2.3:a:ruby-lang:net\\:\\:imap:*:*:*:*:*:ruby:*:*",
            "range":  [
                {
                    "introduced":  "0.5.0"
                },
                {
                    "fixed":  "0.5.14"
                }
            ],
            "source":  "CPE_RANGE"
        },
        {
            "cpe":  "cpe:2.3:a:ruby-lang:net\\:\\:imap:*:*:*:*:*:ruby:*:*",
            "range":  [
                {
                    "introduced":  "0.6.0"
                },
                {
                    "fixed":  "0.6.4"
                }
            ],
            "source":  "CPE_RANGE"
        },
        {
            "range":  [
                {
                    "fixed":  "0ede4c40b1523dfeaf95777b2678e54cc0fd9618"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "range":  [
                {
                    "fixed":  "24a4e770b43230286a05aa2a9746cdbb3eb8485e"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "range":  [
                {
                    "fixed":  "97e2488fb5401a1783bddd959dde007d9fbce42c"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "range":  [
                {
                    "fixed":  "f79d35bf5833f186e81044c57c843eda30c873da"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "original_tag":  "v0.3.10",
            "range":  [
                {
                    "fixed":  "ec89812d3c986d6394d3bc0b93048e704aec6af9"
                }
            ],
            "source":  "REFERENCES_TAG"
        },
        {
            "original_tag":  "v0.4.24",
            "range":  [
                {
                    "fixed":  "24a4e770b43230286a05aa2a9746cdbb3eb8485e"
                }
            ],
            "source":  "REFERENCES_TAG"
        },
        {
            "original_tag":  "v0.5.14",
            "range":  [
                {
                    "fixed":  "4063bc1d1d3e21046544ed7a2c131e5f886bab01"
                }
            ],
            "source":  "REFERENCES_TAG"
        }
    ]
}

Affected versions

v0.*
v0.1.0
v0.1.1
v0.2.0
v0.2.1
v0.2.2
v0.2.3
v0.3.0
v0.3.1
v0.3.2
v0.3.3
v0.3.4
v0.3.5
v0.3.6
v0.3.7
v0.3.8
v0.3.9
v0.4.0
v0.4.1
v0.4.10
v0.4.11
v0.4.12
v0.4.13
v0.4.14
v0.4.15
v0.4.16
v0.4.17
v0.4.18
v0.4.19
v0.4.2
v0.4.20
v0.4.21
v0.4.22
v0.4.23
v0.4.3
v0.4.4
v0.4.5
v0.4.6
v0.4.7
v0.4.8
v0.4.9
v0.5.0
v0.5.1
v0.5.10
v0.5.11
v0.5.12
v0.5.13
v0.5.2
v0.5.3
v0.5.4
v0.5.5
v0.5.6
v0.5.7
v0.5.8
v0.5.9
v0.6.0
v0.6.2

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42246.json"