Linux Distros Unpatched Vulnerability : CVE-2026-73637

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

include('compat.inc');

if (description)
{
  script_id(362622);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/03");

  script_cve_id("CVE-2026-73637");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-73637");

  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.

  - Use after free in mod_auth_digest in Apache Software Foundation Apache HTTP Server before 2.4.69 on all
    platforms allows an unauthenticated remote client to cause authentication state corruption via concurrent
    Digest authentication requests when AuthDigestNcCheck is enabled or AuthDigestNonceLifetime is set to 0.
    Users are recommended to upgrade to version 2.4.69, which fixes this issue. (CVE-2026-73637)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/cve-2026-73637");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-73637");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-73637");
  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:M/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:L/I:L/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-2026-73637");

  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:"2026/10/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/02");

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  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04:-:lts");
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  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
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  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");
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  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:12.0");
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  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:httpd");
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  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:httpd-tools");
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  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:apache2");
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  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/CentOS Linux-7", "Host/OS/CentOS Linux-8", "Host/OS/Debian Linux-12", "Host/OS/Debian Linux-13", "Host/OS/Debian Linux-14", "Host/OS/Red Hat Enterprise Linux-10", "Host/OS/Red Hat Enterprise Linux-7", "Host/OS/Red Hat Enterprise Linux-8", "Host/OS/Red Hat Enterprise Linux-9", "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);
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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/CentOS/rpm-list")) && empty_or_null(get_one_kb_item("Host/Debian/dpkg-l")) && empty_or_null(get_one_kb_item("Host/RedHat/rpm-list"))) 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": "apache2"},
          {"reference": "apache2-bin"},
          {"reference": "apache2-data"},
          {"reference": "apache2-dev"},
          {"reference": "apache2-doc"},
          {"reference": "apache2-ssl-dev"},
          {"reference": "apache2-suexec-custom"},
          {"reference": "apache2-suexec-pristine"},
          {"reference": "apache2-utils"},
          {"reference": "libapache2-mod-md"},
          {"reference": "libapache2-mod-proxy-uwsgi"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "apache2"},
          {"reference": "apache2-bin"},
          {"reference": "apache2-data"},
          {"reference": "apache2-dev"},
          {"reference": "apache2-doc"},
          {"reference": "apache2-ssl-dev"},
          {"reference": "apache2-suexec-custom"},
          {"reference": "apache2-suexec-pristine"},
          {"reference": "apache2-utils"},
          {"reference": "libapache2-mod-md"},
          {"reference": "libapache2-mod-proxy-uwsgi"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "apache2"},
          {"reference": "apache2-bin"},
          {"reference": "apache2-data"},
          {"reference": "apache2-dev"},
          {"reference": "apache2-doc"},
          {"reference": "apache2-ssl-dev"},
          {"reference": "apache2-suexec-custom"},
          {"reference": "apache2-suexec-pristine"},
          {"reference": "apache2-utils"},
          {"reference": "libapache2-mod-md"},
          {"reference": "libapache2-mod-proxy-uwsgi"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "apache2"},
          {"reference": "apache2-bin"},
          {"reference": "apache2-data"},
          {"reference": "apache2-dev"},
          {"reference": "apache2-doc"},
          {"reference": "apache2-ssl-dev"},
          {"reference": "apache2-suexec-custom"},
          {"reference": "apache2-suexec-pristine"},
          {"reference": "apache2-utils"},
          {"reference": "libapache2-mod-md"},
          {"reference": "libapache2-mod-proxy-uwsgi"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "apache2"},
          {"reference": "apache2-bin"},
          {"reference": "apache2-data"},
          {"reference": "apache2-dev"},
          {"reference": "apache2-doc"},
          {"reference": "apache2-ssl-dev"},
          {"reference": "apache2-suexec-custom"},
          {"reference": "apache2-suexec-pristine"},
          {"reference": "apache2-utils"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "apache2"},
          {"reference": "apache2-bin"},
          {"reference": "apache2-data"},
          {"reference": "apache2-dev"},
          {"reference": "apache2-doc"},
          {"reference": "apache2-ssl-dev"},
          {"reference": "apache2-suexec-custom"},
          {"reference": "apache2-suexec-pristine"},
          {"reference": "apache2-utils"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.04",
        "pkgs": [
          {"reference": "apache2"},
          {"reference": "apache2-bin"},
          {"reference": "apache2-data"},
          {"reference": "apache2-dev"},
          {"reference": "apache2-doc"},
          {"reference": "apache2-ssl-dev"},
          {"reference": "apache2-suexec-custom"},
          {"reference": "apache2-suexec-pristine"},
          {"reference": "apache2-utils"}
        ]
      }
    ]
  },
  "Ubuntu Linux-14.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14.04",
        "pkgs": [
          {"reference": "apache2"},
          {"reference": "apache2-bin"},
          {"reference": "apache2-data"},
          {"reference": "apache2-dbg"},
          {"reference": "apache2-dev"},
          {"reference": "apache2-doc"},
          {"reference": "apache2-mpm-event"},
          {"reference": "apache2-mpm-itk"},
          {"reference": "apache2-mpm-prefork"},
          {"reference": "apache2-mpm-worker"},
          {"reference": "apache2-suexec"},
          {"reference": "apache2-suexec-custom"},
          {"reference": "apache2-suexec-pristine"},
          {"reference": "apache2-utils"},
          {"reference": "apache2.2-bin"},
          {"reference": "libapache2-mod-macro"},
          {"reference": "libapache2-mod-proxy-html"}
        ]
      }
    ]
  },
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "apache2"},
          {"reference": "apache2-bin"},
          {"reference": "apache2-data"},
          {"reference": "apache2-dbg"},
          {"reference": "apache2-dev"},
          {"reference": "apache2-doc"},
          {"reference": "apache2-suexec-custom"},
          {"reference": "apache2-suexec-pristine"},
          {"reference": "apache2-utils"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "apache2"},
          {"reference": "apache2-bin"},
          {"reference": "apache2-data"},
          {"reference": "apache2-dbg"},
          {"reference": "apache2-dev"},
          {"reference": "apache2-doc"},
          {"reference": "apache2-ssl-dev"},
          {"reference": "apache2-suexec-custom"},
          {"reference": "apache2-suexec-pristine"},
          {"reference": "apache2-utils"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-10": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "10",
        "pkgs": [
          {"reference": "httpd"},
          {"reference": "httpd-core"},
          {"reference": "httpd-devel"},
          {"reference": "httpd-filesystem"},
          {"reference": "httpd-manual"},
          {"reference": "httpd-tools"},
          {"reference": "mod_ldap"},
          {"reference": "mod_lua"},
          {"reference": "mod_proxy_html"},
          {"reference": "mod_session"},
          {"reference": "mod_ssl"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "httpd"},
          {"reference": "httpd-core"},
          {"reference": "httpd-devel"},
          {"reference": "httpd-filesystem"},
          {"reference": "httpd-manual"},
          {"reference": "httpd-tools"},
          {"reference": "mod_ldap"},
          {"reference": "mod_lua"},
          {"reference": "mod_proxy_html"},
          {"reference": "mod_session"},
          {"reference": "mod_ssl"}
        ]
      }
    ]
  },
  "CentOS Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "httpd"},
          {"reference": "httpd-devel"},
          {"reference": "httpd-manual"},
          {"reference": "httpd-tools"},
          {"reference": "mod_ldap"},
          {"reference": "mod_proxy_html"},
          {"reference": "mod_session"},
          {"reference": "mod_ssl"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "httpd"},
          {"reference": "httpd-devel"},
          {"reference": "httpd-manual"},
          {"reference": "httpd-tools"},
          {"reference": "mod_ldap"},
          {"reference": "mod_proxy_html"},
          {"reference": "mod_session"},
          {"reference": "mod_ssl"}
        ]
      }
    ]
  },
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "httpd"},
          {"reference": "httpd-devel"},
          {"reference": "httpd-filesystem"},
          {"reference": "httpd-manual"},
          {"reference": "httpd-tools"},
          {"reference": "mod_http2"},
          {"reference": "mod_ldap"},
          {"reference": "mod_md"},
          {"reference": "mod_proxy_html"},
          {"reference": "mod_session"},
          {"reference": "mod_ssl"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "httpd"},
          {"reference": "httpd-devel"},
          {"reference": "httpd-filesystem"},
          {"reference": "httpd-manual"},
          {"reference": "httpd-tools"},
          {"reference": "mod_http2"},
          {"reference": "mod_ldap"},
          {"reference": "mod_md"},
          {"reference": "mod_proxy_html"},
          {"reference": "mod_session"},
          {"reference": "mod_ssl"}
        ]
      }
    ]
  }
};

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');
}