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 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. This will cause the first command to eventually fail, but also prevents it from returning until another command is sent (from another thread). That other command will not return until the connection is closed. 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 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. This will cause the     first command to eventually fail, but also prevents it from returning until another command is sent (from     another thread). That other command will not return until the connection is closed. This vulnerability is     fixed in 0.6.5 and 0.5.15. (CVE-2026-47241)

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 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. This will cause the
    first command to eventually fail, but also prevents it from returning until another command is sent (from
    another thread). That other command will not return until the connection is closed. This vulnerability is
    fixed in 0.6.5 and 0.5.15. (CVE-2026-47241)

ID	Name	Product	Family	Severity
323668	Linux Distros Unpatched Vulnerability : CVE-2026-47241	Nessus	Misc.	low
321503	Ruby net-imap < 0.5.15 / 0.6.x < 0.6.4.1 Multiple Vulnerabilities	Nessus	Misc.	medium
442840	SCA: security update for net-imap (GHSA-c4fp-cxrr-mj66)	Tenable Cloud Security	SCA Checks	low
442840	SCA: security update for net-imap (GHSA-c4fp-cxrr-mj66)	Tenable Self-Hosted Container Security	SCA Checks	low

Detections

Analytics

CVE-2026-47241

low

Tenable Plugins

low

medium

low

low