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
Related
Published
2026-05-09T19:33:17.880Z
Modified
2026-07-09T03:52:10.027344897Z
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 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42246.json",
    "cwe_ids": [
        "CWE-392",
        "CWE-393",
        "CWE-636",
        "CWE-754",
        "CWE-841"
    ],
    "cna_assigner": "GitHub_M"
}
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 
{
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ],
    "cpe": "cpe:2.3:a:ruby-lang:net\\:\\:imap:*:*:*:*:*:ruby:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "0.3.10"
        },
        {
            "introduced": "0.4.0"
        },
        {
            "fixed": "0.4.24"
        },
        {
            "introduced": "0.5.0"
        },
        {
            "fixed": "0.5.14"
        },
        {
            "introduced": "0.6.0"
        },
        {
            "fixed": "0.6.4"
        }
    ]
}

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"