Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to 0.6.5 and 0.5.15, when Net::IMAP#id is called with a hash argument, although the ID field value strings are correctly quoted (escaping quoted specials), they were not validated to prohibit CRLF sequences. While Net::IMAP#enable does process its arguments for aliases, it does not validate them as valid atoms (or as a list of valid atoms). The #to_s value is sent verbatim. Arguments to either command could be used by an attacker to inject arbitrary IMAP commands. This vulnerability is fixed in 0.6.5 and 0.5.15.

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:3090-1 advisory.

    This update for ruby3.4 fixes the following issues

    - CVE-2026-42258: Net:IMAP: Command Injection via Symbol Arguments (bsc#1268011).
    - CVE-2026-47240: Net:IMAP: Command Injection via non-synchronizing literal in 'raw' argument     (bsc#1268337).
    - CVE-2026-47241: Net:IMAP: Denial of Service via incomplete raw argument validation (bsc#1268338).
    - CVE-2026-47242: Net:IMAP: Command Injection via ID and ENABLE command arguments (bsc#1268339).
    - CVE-2025-61594: merging URIs using the + operator could expose sensitive user credentials (bsc#1270034).

    Changes for ruby3.4:

    - Update to 3.4.10:

      - bundling net-imap 0.5.15.

Tenable has extracted the preceding description block directly from the SUSE security advisory.

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

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, when Net::IMAP#id is called with a hash argument, although the ID field value strings are     correctly quoted (escaping quoted specials), they were not validated to prohibit CRLF sequences. While     Net::IMAP#enable does process its arguments for aliases, it does not validate them as valid atoms (or as a     list of valid atoms). The #to_s value is sent verbatim. Arguments to either command could be used by an     attacker to inject arbitrary IMAP commands. This vulnerability is fixed in 0.6.5 and 0.5.15.
    (CVE-2026-47242)

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.

ID	Name	Product	Family	Severity
327730	SUSE SLED15: libruby3_4-3_4 / ruby3.4 / ruby3.4-devel / ruby3.4-devel-extra / etc (SUSE-SU-2026:3090-1)	Nessus	SuSE Local Security Checks	medium
323665	Linux Distros Unpatched Vulnerability : CVE-2026-47242	Nessus	Misc.	medium
321503	Ruby net-imap < 0.5.15 / 0.6.x < 0.6.4.1 Multiple Vulnerabilities	Nessus	Misc.	medium

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CVE-2026-47242

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