Linux Distros Unpatched Vulnerability : CVE-2026-106454

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(371387);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/23");

  script_cve_id("CVE-2026-106454");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-106454");

  script_set_attribute(attribute:"synopsis", value:
"The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be
patched.");
  script_set_attribute(attribute:"description", value:
"The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied
patch available.

  - Twisted is an event-based framework for internet applications, supporting Python 3.6+. In 25.5.0 and
    earlier, wildcardToRegexp() in twisted/mail/imap4.py translates the IMAP asterisk and percent wildcards
    but passes all other characters from an authenticated client's LIST or LSUB pattern directly to
    re.compile(), allowing nested or otherwise expensive regular expression constructs to cause catastrophic
    backtracking when matched against mailbox names. Because Twisted uses a cooperative single-threaded
    reactor, the blocking match suspends all server input and output for the duration of the match. No fixed
    release is available as of this review. (CVE-2026-106454)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-106454");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-106454");
  script_set_attribute(attribute:"solution", value:
"There is no known solution at this time.");
  script_set_attribute(attribute:"agent", value:"unix");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:N/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-106454");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_set_attribute(attribute:"vendor_unpatched", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/10/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/23");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:22.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:24.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:26.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:12.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:13.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:twisted");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:twisted");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl", "set_linux_os_id.nasl");
  script_require_keys("Host/cpu", "Host/local_checks_enabled", "global_settings/vendor_unpatched", "Host/OS/identifier");
  script_require_ports("Host/OS/Debian Linux-12", "Host/OS/Debian Linux-13", "Host/OS/Ubuntu Linux-14.04", "Host/OS/Ubuntu Linux-16.04", "Host/OS/Ubuntu Linux-18.04", "Host/OS/Ubuntu Linux-20.04", "Host/OS/Ubuntu Linux-22.04", "Host/OS/Ubuntu Linux-24.04", "Host/OS/Ubuntu Linux-26.04");

  exit(0);
}

if (!get_kb_item("global_settings/vendor_unpatched")) exit(0, "Unpatched Vulnerabilities Detection not active.");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (empty_or_null(get_one_kb_item("Host/Debian/dpkg-l"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Debian Linux-12": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "12",
        "pkgs": [
          {"reference": "python3-twisted"},
          {"reference": "twisted-doc"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "python3-twisted"},
          {"reference": "twisted-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "python3-twisted"},
          {"reference": "twisted-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "python3-twisted"},
          {"reference": "twisted-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.04",
        "pkgs": [
          {"reference": "python3-twisted"},
          {"reference": "twisted-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-14.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14.04",
        "pkgs": [
          {"reference": "python-twisted"},
          {"reference": "python-twisted-bin"},
          {"reference": "python-twisted-bin-dbg"},
          {"reference": "python-twisted-conch"},
          {"reference": "python-twisted-core"},
          {"reference": "python-twisted-lore"},
          {"reference": "python-twisted-mail"},
          {"reference": "python-twisted-names"},
          {"reference": "python-twisted-news"},
          {"reference": "python-twisted-runner"},
          {"reference": "python-twisted-runner-dbg"},
          {"reference": "python-twisted-web"},
          {"reference": "python-twisted-words"},
          {"reference": "twisted-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "python-twisted"},
          {"reference": "python-twisted-bin"},
          {"reference": "python-twisted-bin-dbg"},
          {"reference": "python-twisted-conch"},
          {"reference": "python-twisted-core"},
          {"reference": "python-twisted-mail"},
          {"reference": "python-twisted-names"},
          {"reference": "python-twisted-news"},
          {"reference": "python-twisted-runner"},
          {"reference": "python-twisted-runner-dbg"},
          {"reference": "python-twisted-web"},
          {"reference": "python-twisted-words"},
          {"reference": "python3-twisted"},
          {"reference": "twisted-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "python-twisted"},
          {"reference": "python-twisted-bin"},
          {"reference": "python-twisted-bin-dbg"},
          {"reference": "python-twisted-conch"},
          {"reference": "python-twisted-core"},
          {"reference": "python-twisted-mail"},
          {"reference": "python-twisted-names"},
          {"reference": "python-twisted-news"},
          {"reference": "python-twisted-runner"},
          {"reference": "python-twisted-runner-dbg"},
          {"reference": "python-twisted-web"},
          {"reference": "python-twisted-words"},
          {"reference": "python3-twisted"},
          {"reference": "python3-twisted-bin"},
          {"reference": "python3-twisted-bin-dbg"},
          {"reference": "twisted-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "python3-twisted"},
          {"reference": "python3-twisted-bin"},
          {"reference": "python3-twisted-bin-dbg"},
          {"reference": "twisted-doc"}
        ]
      }
    ]
  }
};

var distro_constraints_values = linux_unpatched::get_distro_constraints(distro_constraints_arr:distro_constraints_array);
if (empty_or_null(distro_constraints_values)) audit(AUDIT_HOST_NOT, 'affected');

var third_party_support = get_kb_item('Host/OS/extended-third-party');
if (!empty_or_null(third_party_support)) {
    var third_party_vendors = distro_constraints_values['third_party'];
    if (!empty_or_null(third_party_vendors)) {
        var vendor;
        foreach vendor (third_party_vendors) {
            if (vendor == third_party_support) exit(0, 'A third party management patch is available for this vulnerability from ' + vendor + '.\n');
        }
    }
}

var report = linux_unpatched::check_unpatched_constraints(distro_constraints_values:distro_constraints_values);

if (!empty_or_null(report))
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}