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7.6

Net::IMAP in Ruby allows malicious IMAP command injection

DEBIAN-CVE-2026-42257
Summary

The Net::IMAP library in Ruby has a security issue. If a user enters malicious input, it could be used to execute unauthorized commands on the email server. This issue has been fixed in versions 0.4.24, 0.5.14, and 0.6.4. If you're using an earlier version, you should update to a fixed version to prevent potential security risks.

What to do

No fix is available yet. Check with your software vendor for updates.

Affected software
Ecosystem VendorProductAffected versions
Debian:11 debian ruby2.7 All versions
Debian:12 debian ruby3.1 All versions
Debian:13 debian ruby3.3 All versions
Debian:14 debian ruby3.3 All versions
Original title
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 ...
Original description
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 CVSS4.0 7.6
Published: 9 May 2026 · Updated: 19 May 2026 · First seen: 16 May 2026