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.

tencent_linux TSSA-2026:0933: TSSA-2026:0933: ruby:3.3 security, bug fix, and enhancement update (Important)

The remote MiracleLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the AXSA:2026-1667:01 advisory.

    * zlib: zlib: Memory corruption via buffer overflow in Zlib::GzipReader (CVE-2026-27820)
      * net-imap: Net::IMAP: Arbitrary IMAP command injection via CRLF sequences in unvalidated input     (CVE-2026-42257)
      * ruby/net-imap: ruby: Net::IMAP: Denial of Service via large iteration count in SCRAM authentication     (CVE-2026-42256)
      * net-imap: Net::IMAP: Command injection via non-synchronizing literals (CVE-2026-47240)
      * net-imap: Net::IMAP: Arbitrary IMAP command injection due to improper input validation     (CVE-2026-47242)
      * net-imap: rubygem-net-imap: Net::IMAP: Denial of Service via malformed command input (CVE-2026-47241)

Tenable has extracted the preceding description block directly from the MiracleLinux 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 remote RockyLinux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2026:50728 advisory.

    * zlib: zlib: Memory corruption via buffer overflow in Zlib::GzipReader (CVE-2026-27820)

    * net-imap: Net::IMAP: Arbitrary IMAP command injection via CRLF sequences in unvalidated input     (CVE-2026-42257)

    * ruby/net-imap: ruby: Net::IMAP: Denial of Service via large iteration count in SCRAM authentication     (CVE-2026-42256)

    * net-imap: Net::IMAP: Command injection via non-synchronizing literals (CVE-2026-47240)

    * net-imap: Net::IMAP: Arbitrary IMAP command injection due to improper input validation (CVE-2026-47242)

    * net-imap: rubygem-net-imap: Net::IMAP: Denial of Service via malformed command input (CVE-2026-47241)

    Bug Fix(es) and Enhancement(s):

    * ruby:3.3/ruby: Rebase to the latest Ruby 3.3 release [rhel-8] (JIRA:Rocky Linux-170929)

Tenable has extracted the preceding description block directly from the RockyLinux 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 remote RockyLinux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2026:50778 advisory.

    * zlib: zlib: Memory corruption via buffer overflow in Zlib::GzipReader (CVE-2026-27820)

    * net-imap: Net::IMAP: Arbitrary IMAP command injection via CRLF sequences in unvalidated input     (CVE-2026-42257)

    * ruby/net-imap: ruby: Net::IMAP: Denial of Service via large iteration count in SCRAM authentication     (CVE-2026-42256)

    * net-imap: Net::IMAP: Command injection via non-synchronizing literals (CVE-2026-47240)

    * net-imap: Net::IMAP: Arbitrary IMAP command injection due to improper input validation (CVE-2026-47242)

    * net-imap: rubygem-net-imap: Net::IMAP: Denial of Service via malformed command input (CVE-2026-47241)

    Bug Fix(es) and Enhancement(s):

    * ruby: Rebase to the latest Ruby 3.3 release [rhel-10.2.z] (JIRA:Rocky Linux-211300)

Tenable has extracted the preceding description block directly from the RockyLinux 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 remote RockyLinux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2026:50773 advisory.

    * zlib: zlib: Memory corruption via buffer overflow in Zlib::GzipReader (CVE-2026-27820)

    * net-imap: Net::IMAP: Arbitrary IMAP command injection via CRLF sequences in unvalidated input     (CVE-2026-42257)

    * ruby/net-imap: ruby: Net::IMAP: Denial of Service via large iteration count in SCRAM authentication     (CVE-2026-42256)

    * net-imap: Net::IMAP: Command injection via non-synchronizing literals (CVE-2026-47240)

    * net-imap: Net::IMAP: Arbitrary IMAP command injection due to improper input validation (CVE-2026-47242)

    * net-imap: rubygem-net-imap: Net::IMAP: Denial of Service via malformed command input (CVE-2026-47241)

    Bug Fix(es) and Enhancement(s):

    * ruby4.0: Rebase to the latest Ruby 4.0 release [rhel-10.2.z] (JIRA:Rocky Linux-211310)

Tenable has extracted the preceding description block directly from the RockyLinux 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 remote RockyLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2026:50828 advisory.

    * zlib: zlib: Memory corruption via buffer overflow in Zlib::GzipReader (CVE-2026-27820)

    * net-imap: Net::IMAP: Arbitrary IMAP command injection via CRLF sequences in unvalidated input     (CVE-2026-42257)

    * ruby/net-imap: ruby: Net::IMAP: Denial of Service via large iteration count in SCRAM authentication     (CVE-2026-42256)

    * net-imap: Net::IMAP: Command injection via non-synchronizing literals (CVE-2026-47240)

    * net-imap: Net::IMAP: Arbitrary IMAP command injection due to improper input validation (CVE-2026-47242)

    * net-imap: rubygem-net-imap: Net::IMAP: Denial of Service via malformed command input (CVE-2026-47241)

    Bug Fix(es) and Enhancement(s):

    * ruby:3.3/ruby: Rebase to the latest Ruby 3.3 release [rhel-9.8.z] (JIRA:Rocky Linux-171335)

Tenable has extracted the preceding description block directly from the RockyLinux 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 remote RockyLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2026:50827 advisory.

    * zlib: zlib: Memory corruption via buffer overflow in Zlib::GzipReader (CVE-2026-27820)

    * net-imap: Net::IMAP: Arbitrary IMAP command injection via CRLF sequences in unvalidated input     (CVE-2026-42257)

    * ruby/net-imap: ruby: Net::IMAP: Denial of Service via large iteration count in SCRAM authentication     (CVE-2026-42256)

    * net-imap: Net::IMAP: Command injection via non-synchronizing literals (CVE-2026-47240)

    * net-imap: Net::IMAP: Arbitrary IMAP command injection due to improper input validation (CVE-2026-47242)

    * net-imap: rubygem-net-imap: Net::IMAP: Denial of Service via malformed command input (CVE-2026-47241)

    Bug Fix(es) and Enhancement(s):

    * ruby:4.0/ruby: Rebase to the latest Ruby 4.0 release [rhel-9.8.z] (JIRA:Rocky Linux-211301)

Tenable has extracted the preceding description block directly from the RockyLinux 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 remote MiracleLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the AXSA:2026-1647:01 advisory.

    * zlib: zlib: Memory corruption via buffer overflow in Zlib::GzipReader (CVE-2026-27820)
      * net-imap: Net::IMAP: Arbitrary IMAP command injection via CRLF sequences in unvalidated input     (CVE-2026-42257)
      * ruby/net-imap: ruby: Net::IMAP: Denial of Service via large iteration count in SCRAM authentication     (CVE-2026-42256)
      * net-imap: Net::IMAP: Command injection via non-synchronizing literals (CVE-2026-47240)
      * net-imap: Net::IMAP: Arbitrary IMAP command injection due to improper input validation     (CVE-2026-47242)
      * net-imap: rubygem-net-imap: Net::IMAP: Denial of Service via malformed command input (CVE-2026-47241)

Tenable has extracted the preceding description block directly from the MiracleLinux 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 remote Oracle Linux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2026-50778 advisory.

    [3.3.12-14]
    - Upgrade to Ruby 3.3.12.
      Resolves: RHEL-211300       Resolves: RHEL-193659

Tenable has extracted the preceding description block directly from the Oracle Linux 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 remote Oracle Linux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2026-50773 advisory.

    [4.0.6-36]
    - Upgrade to Ruby 4.0.6.
      Resolves: RHEL-211310       Resolves: RHEL-193660

Tenable has extracted the preceding description block directly from the Oracle Linux 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 remote Oracle Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2026-50728 advisory.

    ruby     [3.3.12-8]
    - Upgrade to Ruby 3.3.12.
      Resolves: RHEL-170929       Resolves: RHEL-193664

    rubygem-abrt     rubygem-mysql2     rubygem-pg

Tenable has extracted the preceding description block directly from the Oracle Linux 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 remote Oracle Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2026-50827 advisory.

    ruby     [4.0.6-34]
    - Upgrade to Ruby 4.0.6.
      Resolves: RHEL-211301       Resolves: RHEL-193663

    rubygem-mysql2     [0.5.7-1]
    - Upgrade to mysql2 0.5.7.
      Related: RHEL-142278

    [0.5.5-3]
    - Disable tests on the 32bit platforms ix86.
      Related: RHEL-80222

    [0.5.5-2]
    - Adapt tests to openssl 3.2       Resolves: RHEL-80222

    rubygem-pg     [1.6.3-1]
    - Upgrade to pg 1.6.3       Related: RHEL-142278

Tenable has extracted the preceding description block directly from the Oracle Linux 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 remote Oracle Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2026-50828 advisory.

    ruby     [3.3.12-8]
    - Upgrade to Ruby 3.3.12.
      Resolves: RHEL-171335       Resolves: RHEL-193665

    rubygem-mysql2     [0.5.5-3]
    - Disable tests on the 32bit platforms ix86.
      Related: RHEL-80222

    [0.5.5-2]
    - Adapt tests to openssl 3.2       Resolves: RHEL-80222

    [0.5.5-1]
    - Upgrade to mysql2 0.5.5.
      Related: RHEL-17089

    rubygem-pg     [-1.5.4-2]
    - Fix encoding issue in spec suite.
      Resolves: RHEL-159199

Tenable has extracted the preceding description block directly from the Oracle Linux 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 remote MiracleLinux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the AXSA:2026-1503:01 advisory.

    * zlib: zlib: Memory corruption via buffer overflow in Zlib::GzipReader (CVE-2026-27820)
      * net-imap: Net::IMAP: Arbitrary IMAP command injection via CRLF sequences in unvalidated input     (CVE-2026-42257)
      * ruby/net-imap: ruby: Net::IMAP: Denial of Service via large iteration count in SCRAM authentication     (CVE-2026-42256)
      * net-imap: Net::IMAP: Command injection via non-synchronizing literals (CVE-2026-47240)
      * net-imap: Net::IMAP: Arbitrary IMAP command injection due to improper input validation     (CVE-2026-47242)
      * net-imap: rubygem-net-imap: Net::IMAP: Denial of Service via malformed command input (CVE-2026-47241)

Tenable has extracted the preceding description block directly from the MiracleLinux 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 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	Type	Severity
341076	MiracleLinux 9 : ruby:4.0 (AXSA:2026-1667:01)	Nessus	Miracle Linux Local Security Checks	Local	medium
341008	RockyLinux 8 : ruby:3.3 (RLSA-2026:50728)	Nessus	Rocky Linux Local Security Checks	Local	medium
341007	RockyLinux 10 : ruby (RLSA-2026:50778)	Nessus	Rocky Linux Local Security Checks	Local	medium
341006	RockyLinux 10 : ruby4.0 (RLSA-2026:50773)	Nessus	Rocky Linux Local Security Checks	Local	medium
341005	RockyLinux 9 : ruby:3.3 (RLSA-2026:50828)	Nessus	Rocky Linux Local Security Checks	Local	medium
341004	RockyLinux 9 : ruby:4.0 (RLSA-2026:50827)	Nessus	Rocky Linux Local Security Checks	Local	medium
339405	MiracleLinux 9 : ruby:3.3 (AXSA:2026-1647:01)	Nessus	Miracle Linux Local Security Checks	Local	medium
335471	Oracle Linux 10 : ruby (ELSA-2026-50778)	Nessus	Oracle Linux Local Security Checks	Local	medium
335469	Oracle Linux 10 : ruby4.0 (ELSA-2026-50773)	Nessus	Oracle Linux Local Security Checks	Local	medium
334429	Oracle Linux 8 : ruby:3.3 (ELSA-2026-50728)	Nessus	Oracle Linux Local Security Checks	Local	medium
334161	Oracle Linux 9 : ruby:4.0 (ELSA-2026-50827)	Nessus	Oracle Linux Local Security Checks	Local	medium
334141	Oracle Linux 9 : ruby:3.3 (ELSA-2026-50828)	Nessus	Oracle Linux Local Security Checks	Local	medium
333609	MiracleLinux 8 : ruby:3.3 (AXSA:2026-1503:01)	Nessus	Miracle Linux Local Security Checks	Local	medium
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	Local	medium
323665	Linux Distros Unpatched Vulnerability : CVE-2026-47242	Nessus	Misc.	Local	medium
321503	Ruby net-imap < 0.5.15 / 0.6.x < 0.6.4.1 Multiple Vulnerabilities	Nessus	Misc.	Local	medium

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