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-2026-42257

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-2026-42245

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-2026-42258

CVE-2026-42258 affects the Ruby Net::IMAP client. The issue is a CRLF/IMAP command injection via symbol arguments passed to commands, exploitable in versions prior to 0.4.24, 0.5.14, and 0.6.4. The vulnerability root cause is unvalidated Symbol inputs being used in IMAP command handling, enabling...