Medium
net-imap: Command Injection via "raw" arguments to multiple commands
Type: advisorySources: OSV
Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.4.24, 0.5.14, and 0.6.4, several Net::IMAP commands accept a raw string argument that is sent to the server without validation or escaping. If this string is derived from user-controlled input, it may contain contain CRLF sequences, which an attacker can use to inject arbitrary IMAP commands. This issue has been patched in versions 0.4.24, 0.5.14, and 0.6.4.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-42257
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 7 Nov 2026, 08:20 UTC · Revision 1
Source evidence
net-imap: Command Injection via "raw" arguments to multiple commands
core-osv · Original sourcePublished 9 May 2026, 19:39 UTC
Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.4.24, 0.5.14, and 0.6.4, several Net::IMAP commands accept a raw string argument that is sent to the server without validation or escaping. If this string is derived from user-controlled input, it may contain contain CRLF sequences, which an attacker can use to inject arbitrary IMAP commands. This issue has been patched in versions 0.4.24, 0.5.14, and 0.6.4.
osv:CVE-2026-42257
Complete source record
{
"id": "9d87b4b50687189e96f99645970b29793992edf48547093ed2fdadd96a38d9d6",
"url": "https://osv.dev/vulnerability/CVE-2026-42257",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "net-imap: Command Injection via \"raw\" arguments to multiple commands",
"summary": "Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.4.24, 0.5.14, and 0.6.4, several Net::IMAP commands accept a raw string argument that is sent to the server without validation or escaping. If this string is derived from user-controlled input, it may contain contain CRLF sequences, which an attacker can use to inject arbitrary IMAP commands. This issue has been patched in versions 0.4.24, 0.5.14, and 0.6.4.",
"evidence": "osv:CVE-2026-42257",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2026-42257",
"aliases": [
"CVE-2026-42257",
"GHSA-hm49-wcqc-g2xg"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/ruby/net-imap",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "24a4e770b43230286a05aa2a9746cdbb3eb8485e"
},
{
"introduced": "cc13c91c65b78ee33ebf4960d547173e761cafdc"
},
{
"fixed": "4063bc1d1d3e21046544ed7a2c131e5f886bab01"
},
{
"introduced": "567518cae5500f7c4776a1fd4e9bbd599e98b9bf"
},
{
"fixed": "3e490673dca65d0cfeeeb3fbf1fdaa188d6f27c4"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:ruby-lang:net\\:\\:imap:*:*:*:*:*:ruby:*:*",
"range": [
{
"introduced": "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": "24a4e770b43230286a05aa2a9746cdbb3eb8485e"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v0.4.24"
},
{
"range": [
{
"fixed": "4063bc1d1d3e21046544ed7a2c131e5f886bab01"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v0.5.14"
},
{
"range": [
{
"fixed": "3e490673dca65d0cfeeeb3fbf1fdaa188d6f27c4"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v0.6.4"
}
]
}
}
],
"versions": [
"v0.4.23",
"v0.5.13",
"v0.6.2",
"v0.4.22",
"v0.6.0",
"v0.5.12",
"v0.5.11",
"v0.5.10",
"v0.5.9",
"v0.4.21",
"v0.5.8",
"v0.4.20",
"v0.5.7",
"v0.4.19",
"v0.5.6",
"v0.4.18",
"v0.5.5",
"v0.5.4",
"v0.5.3",
"v0.5.2",
"v0.5.1",
"v0.4.17",
"v0.5.0",
"v0.4.16",
"v0.4.15",
"v0.4.14",
"v0.4.13",
"v0.4.12",
"v0.4.11",
"v0.4.10",
"v0.4.9",
"v0.3.4",
"v0.2.3",
"v0.4.8",
"v0.4.7",
"v0.4.6",
"v0.4.5",
"v0.4.4",
"v0.4.3",
"v0.4.2",
"v0.4.1",
"v0.4.0",
"v0.3.3",
"v0.3.2",
"v0.3.1",
"v0.3.0",
"v0.2.2",
"v0.2.1",
"v0.2.0",
"v0.1.1",
"v0.1.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42257.json"
}
}
],
"modified": "2026-10-28T02:30:50.599778976Z",
"provider": "osv",
"references": [
"https://github.com/ruby/net-imap/releases/tag/v0.4.24",
"https://github.com/ruby/net-imap/releases/tag/v0.5.14",
"https://github.com/ruby/net-imap/releases/tag/v0.6.4",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42257.json",
"https://github.com/ruby/net-imap/security/advisories/GHSA-hm49-wcqc-g2xg",
"https://nvd.nist.gov/vuln/detail/CVE-2026-42257"
],
"provider_metadata": {
"cwe_ids": [
"CWE-77",
"CWE-93"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42257.json"
}
},
"related_cves": [
{
"value": "CVE-2026-42257",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 518734,
"published_at": "2026-05-09T19:39:48.398+00:00"
}