CVE-2025-43857

Net::IMAP for Ruby is vulnerable to denial of service via memory exhaustion when processing server responses containing a literal byte count. A malicious server can trigger the client’s receiver thread to allocate memory for the indicated size, potentially exhausting memory during any active conn...

CVE-2026-42246

Net::IMAP (Ruby) versions before 0.3.10, 0.4.24, 0.5.14, and 0.6.4 are affected by a STARTTLS stripping issue. A man-in-the-middle attacker can cause Net::IMAP#starttls to report a successful TLS upgrade without actually enabling TLS, leaving the socket unencrypted. The vulnerability is mitigated...

CVE-2026-42245

Net::IMAP (Ruby) is affected by a performance vulnerability in Net::IMAP::ResponseReader, where reading large responses with many string literals causes quadratic time complexity. This can be exploited by a hostile server to exhaust the client’s CPU, leading to a denial of service. The issue has ...

CVE-2026-42257

CVE-2026-42257 affects the Ruby Net::IMAP library where, prior to versions 0.4.24, 0.5.14, and 0.6.4, several IMAP commands accept a raw string argument sent to the server without validation or escaping. If derived from user input, this can include CRLF sequences and allow injection of arbitrary ...

CVE-2026-42258

Net::IMAP (Ruby) is affected by CVE-2026-42258: before versions 0.4.24, 0.5.14, and 0.6.4, symbol arguments passed to IMAP commands can be used for CRLF/command injection. The IBM Aspera Shares bulletin and multiple security trackers confirm this vulnerability in Net::IMAP and note patches in 0.4...