HighFix available
ruby-net-imap — security advisory
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.
- Products
- ruby-net-imap
- Affected versions
- Not specified
- Fixed versions
- 0.4.25-r0
- CVEs
- CVE-2026-42246
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 17:57 UTC · Revision 1
Source evidence
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.
osv:ALPINE-CVE-2026-42246
ruby-net-imap
Fixed versions: 0.4.25-r0
Complete source record
{
"id": "a562afec8e64df6662209f1ed8b72e3f2faa8dc034c2b8116b3c909f7f0fdca5",
"url": "https://osv.dev/vulnerability/ALPINE-CVE-2026-42246",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "ALPINE-CVE-2026-42246",
"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.",
"evidence": "osv:ALPINE-CVE-2026-42246",
"products": [
{
"name": {
"value": "ruby-net-imap",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "0.4.25-r0",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
}
],
"severity": "high",
"structured": {
"id": "ALPINE-CVE-2026-42246",
"aliases": [
"ALPINE-CVE-2026-42246"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "0.4.25-r0"
}
]
}
],
"package": {
"name": "ruby-net-imap",
"purl": "pkg:apk/alpine/ruby-net-imap?arch=source",
"ecosystem": "Alpine:v3.21"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-42246.json"
},
"ecosystem_specific": {}
}
],
"modified": "2026-10-27T12:30:04.136365042Z",
"provider": "osv",
"upstream": [
"CVE-2026-42246"
],
"references": [
"https://security.alpinelinux.org/vuln/CVE-2026-42246"
]
},
"related_cves": [
{
"value": "CVE-2026-42246",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 461539,
"published_at": "2026-05-09T20:16:28.163+00:00"
}