by Kastro
Paper/Archive/CVE-2026-42257

CVE-2026-42257

ruby net-imap — net-imap: Command Injection via "raw" arguments to multiple commands

EPSS 0.4%CVSS 9.8
critical.is priorityof 100
37
CVSS 9.8 (NVD)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 37.2.372 × 207.4No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
net-imap< 0.4.24–CNA
net-imap>= 0.5.0, < 0.5.14–CNA
net-imap>= 0.6.0, < 0.6.4–CNA

Scores by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub_M (CNA)5.8CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: partial

References

refgithub.com/ruby/net-imap/security/advisories/GHSA-hm49-wcqc-g2xgrefgithub.com/ruby/net-imap/releases/tag/v0.4.24refgithub.com/ruby/net-imap/releases/tag/v0.5.14refgithub.com/ruby/net-imap/releases/tag/v0.6.4