Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to 0.6.5 and 0.5.15, several Net::IMAP commands accept a "raw data" argument that is sent verbatim after validation to prevent command injection. However, if a server does not support non-synchronizing literals, it may still be possible to inject arbitrary IMAP commands inside non-synchronizing literals. A server without support for non-synchronizing literals may interpret the "+}\r\n" as the end of a malformed command line and respond with a tagged BAD. In that case, the contents of the literal will be interpreted as one or more new pipelined commands, allowing a CRLF command injection attack to succeed. This affects criteria for #search and #uid_search; search_keys for #sort, #thread, #uid_sort, and #uid_thread; and attr for #fetch and #uid_fetch. This vulnerability is fixed in 0.6.5 and 0.5.15.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to 0.6.5     and 0.5.15, several Net::IMAP commands accept a raw data argument that is sent verbatim after validation     to prevent command injection. However, if a server does not support non-synchronizing literals, it may     still be possible to inject arbitrary IMAP commands inside non-synchronizing literals. A server without     support for non-synchronizing literals may interpret the +}\r\n as the end of a malformed command line     and respond with a tagged BAD. In that case, the contents of the literal will be interpreted as one or     more new pipelined commands, allowing a CRLF command injection attack to succeed. This affects criteria     for #search and #uid_search; search_keys for #sort, #thread, #uid_sort, and #uid_thread; and attr for     #fetch and #uid_fetch. This vulnerability is fixed in 0.6.5 and 0.5.15. (CVE-2026-47240)

Note that Nessus relies on the presence of the package as reported by the vendor.

The version of the net-imap Ruby library installed on the remote host is prior to 0.5.15, or 0.6.x prior to 0.6.4.1.
It is, therefore, affected by multiple vulnerabilities.

  - Several Net::IMAP commands accept a raw data argument that is sent verbatim after validation to prevent command     injection. However, if a server does not support non-synchronizing literals, it may still be possible to inject     arbitrary IMAP commands inside non-synchronizing literals. (CVE-2026-47240)

  - Several Net::IMAP commands accept a raw string argument which is only validated to prevent CRLF injection and     then sent verbatim. If this string is derived from user-controlled input, an attacker can force the next command     to be absorbed as a continuation of the first command, causing a denial of service. (CVE-2026-47241)

  - Two Net::IMAP commands, id and enable, do not validate their arguments. Arguments to either command could be     used by an attacker to inject arbitrary IMAP commands. (CVE-2026-47242)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to 0.6.5
    and 0.5.15, several Net::IMAP commands accept a "raw data" argument that is sent verbatim after validation
    to prevent command injection. However, if a server does not support non-synchronizing literals, it may
    still be possible to inject arbitrary IMAP commands inside non-synchronizing literals. A server without
    support for non-synchronizing literals may interpret the "+}\r\n" as the end of a malformed command line
    and respond with a tagged BAD. In that case, the contents of the literal will be interpreted as one or
    more new pipelined commands, allowing a CRLF command injection attack to succeed. This affects criteria
    for #search and #uid_search; search_keys for #sort, #thread, #uid_sort, and #uid_thread; and attr for
    #fetch and #uid_fetch. This vulnerability is fixed in 0.6.5 and 0.5.15. (CVE-2026-47240)

ID	Name	Product	Family	Severity
323667	Linux Distros Unpatched Vulnerability : CVE-2026-47240	Nessus	Misc.	medium
321503	Ruby net-imap < 0.5.15 / 0.6.x < 0.6.4.1 Multiple Vulnerabilities	Nessus	Misc.	medium
442841	SCA: security update for net-imap (GHSA-8p34-64r3-mwg8)	Tenable Cloud Security	SCA Checks	medium
442841	SCA: security update for net-imap (GHSA-8p34-64r3-mwg8)	Tenable Self-Hosted Container Security	SCA Checks	medium

Detections

Analytics

CVE-2026-47240

medium

Tenable Plugins

medium

medium

medium

medium