Linux Distros Unpatched Vulnerability : CVE-2026-27852

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

include('compat.inc');

if (description)
{
  script_id(341520);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/29");

  script_cve_id("CVE-2026-27852");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-27852");

  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.

  - An attacker that can send mail to a user can craft a message whose headers contain a very large number of
    email addresses or MIME parameters, which causes excessive memory usage when the message is later parsed.
    The message is still delivered, but reading it over IMAP can exhaust the memory limit of the process and
    terminate it, causing denial of service for the affected user. Update to non-vulnerable version. No
    publicly available exploits are known. (CVE-2026-27852)

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-2026-27852");
  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:N/C:P/I:P/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:N/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-27852");

  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:"2026/08/28");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/29");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
  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:"cpe:/o:debian:debian_linux:14.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dovecot");
  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-11", "Host/OS/Debian Linux-12", "Host/OS/Debian Linux-13", "Host/OS/Debian Linux-14");

  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-11": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "11",
        "pkgs": [
          {"reference": "dovecot-auth-lua"},
          {"reference": "dovecot-core"},
          {"reference": "dovecot-dev"},
          {"reference": "dovecot-gssapi"},
          {"reference": "dovecot-imapd"},
          {"reference": "dovecot-ldap"},
          {"reference": "dovecot-lmtpd"},
          {"reference": "dovecot-lucene"},
          {"reference": "dovecot-managesieved"},
          {"reference": "dovecot-mysql"},
          {"reference": "dovecot-pgsql"},
          {"reference": "dovecot-pop3d"},
          {"reference": "dovecot-sieve"},
          {"reference": "dovecot-solr"},
          {"reference": "dovecot-sqlite"},
          {"reference": "dovecot-submissiond"}
        ]
      }
    ]
  },
  "Debian Linux-12": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "12",
        "pkgs": [
          {"reference": "dovecot-auth-lua"},
          {"reference": "dovecot-core"},
          {"reference": "dovecot-dev"},
          {"reference": "dovecot-gssapi"},
          {"reference": "dovecot-imapd"},
          {"reference": "dovecot-ldap"},
          {"reference": "dovecot-lmtpd"},
          {"reference": "dovecot-lucene"},
          {"reference": "dovecot-managesieved"},
          {"reference": "dovecot-mysql"},
          {"reference": "dovecot-pgsql"},
          {"reference": "dovecot-pop3d"},
          {"reference": "dovecot-sieve"},
          {"reference": "dovecot-solr"},
          {"reference": "dovecot-sqlite"},
          {"reference": "dovecot-submissiond"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "dovecot-auth-lua"},
          {"reference": "dovecot-core"},
          {"reference": "dovecot-dev"},
          {"reference": "dovecot-flatcurve"},
          {"reference": "dovecot-gssapi"},
          {"reference": "dovecot-imapd"},
          {"reference": "dovecot-ldap"},
          {"reference": "dovecot-lmtpd"},
          {"reference": "dovecot-managesieved"},
          {"reference": "dovecot-mariadb"},
          {"reference": "dovecot-mysql"},
          {"reference": "dovecot-pgsql"},
          {"reference": "dovecot-pop3d"},
          {"reference": "dovecot-sieve"},
          {"reference": "dovecot-solr"},
          {"reference": "dovecot-sqlite"},
          {"reference": "dovecot-submissiond"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "dovecot-auth-lua"},
          {"reference": "dovecot-core"},
          {"reference": "dovecot-dev"},
          {"reference": "dovecot-flatcurve"},
          {"reference": "dovecot-gssapi"},
          {"reference": "dovecot-imapd"},
          {"reference": "dovecot-ldap"},
          {"reference": "dovecot-lmtpd"},
          {"reference": "dovecot-managesieved"},
          {"reference": "dovecot-mysql"},
          {"reference": "dovecot-pgsql"},
          {"reference": "dovecot-pop3d"},
          {"reference": "dovecot-sieve"},
          {"reference": "dovecot-solr"},
          {"reference": "dovecot-sqlite"},
          {"reference": "dovecot-submissiond"}
        ]
      }
    ]
  }
};

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');
}