Linux Distros Unpatched Vulnerability : CVE-2026-109449

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

include('compat.inc');

if (description)
{
  script_id(366826);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/18");

  script_cve_id("CVE-2026-109449");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-109449");

  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.

  - In Symfony Expression Language versions prior to 5.4.54, 6.4.48, 7.4.21, and 8.1.9, the parser of the
    ExpressionLanguage component built its node tree with no bound on its depth. An expression made of tens of
    thousands of nested unary operators, array literals, binary operators or property accesses crashed the PHP
    process, while the tree was being freed. #[Assert\ExpressionSyntax] passes the validated value to
    ExpressionLanguage::lint(), so an application validating expressions written by its users could be crashed
    by a single request, and so could any code parsing untrusted expressions. This issue affects
    symfony/expression-language through v5.4.53, v6.0.0-BETA1 through v6.4.47, v7.0.0-BETA1 through v7.4.20,
    and v8.0.0-BETA1 through v8.1.8. (CVE-2026-109449)

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-2026-109449");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-109449");
  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:S/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:L/UI:N/S:U/C:N/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-109449");

  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:"2026/10/15");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/17");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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:symfony");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:symfony");
  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-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": "php-symfony"},
          {"reference": "php-symfony-asset"},
          {"reference": "php-symfony-browser-kit"},
          {"reference": "php-symfony-cache"},
          {"reference": "php-symfony-config"},
          {"reference": "php-symfony-console"},
          {"reference": "php-symfony-css-selector"},
          {"reference": "php-symfony-dependency-injection"},
          {"reference": "php-symfony-dom-crawler"},
          {"reference": "php-symfony-dotenv"},
          {"reference": "php-symfony-error-handler"},
          {"reference": "php-symfony-event-dispatcher"},
          {"reference": "php-symfony-expression-language"},
          {"reference": "php-symfony-filesystem"},
          {"reference": "php-symfony-finder"},
          {"reference": "php-symfony-form"},
          {"reference": "php-symfony-http-client"},
          {"reference": "php-symfony-http-foundation"},
          {"reference": "php-symfony-http-kernel"},
          {"reference": "php-symfony-inflector"},
          {"reference": "php-symfony-intl"},
          {"reference": "php-symfony-ldap"},
          {"reference": "php-symfony-lock"},
          {"reference": "php-symfony-mailer"},
          {"reference": "php-symfony-messenger"},
          {"reference": "php-symfony-mime"},
          {"reference": "php-symfony-notifier"},
          {"reference": "php-symfony-options-resolver"},
          {"reference": "php-symfony-password-hasher"},
          {"reference": "php-symfony-process"},
          {"reference": "php-symfony-property-access"},
          {"reference": "php-symfony-property-info"},
          {"reference": "php-symfony-rate-limiter"},
          {"reference": "php-symfony-routing"},
          {"reference": "php-symfony-runtime"},
          {"reference": "php-symfony-security-core"},
          {"reference": "php-symfony-security-csrf"},
          {"reference": "php-symfony-security-guard"},
          {"reference": "php-symfony-security-http"},
          {"reference": "php-symfony-semaphore"},
          {"reference": "php-symfony-serializer"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "php-symfony"},
          {"reference": "php-symfony-asset"},
          {"reference": "php-symfony-asset-mapper"},
          {"reference": "php-symfony-browser-kit"},
          {"reference": "php-symfony-cache"},
          {"reference": "php-symfony-clock"},
          {"reference": "php-symfony-config"},
          {"reference": "php-symfony-console"},
          {"reference": "php-symfony-css-selector"},
          {"reference": "php-symfony-dependency-injection"},
          {"reference": "php-symfony-dom-crawler"},
          {"reference": "php-symfony-dotenv"},
          {"reference": "php-symfony-error-handler"},
          {"reference": "php-symfony-event-dispatcher"},
          {"reference": "php-symfony-expression-language"},
          {"reference": "php-symfony-filesystem"},
          {"reference": "php-symfony-finder"},
          {"reference": "php-symfony-form"},
          {"reference": "php-symfony-html-sanitizer"},
          {"reference": "php-symfony-http-client"},
          {"reference": "php-symfony-http-foundation"},
          {"reference": "php-symfony-http-kernel"},
          {"reference": "php-symfony-intl"},
          {"reference": "php-symfony-ldap"},
          {"reference": "php-symfony-lock"},
          {"reference": "php-symfony-mailer"},
          {"reference": "php-symfony-messenger"},
          {"reference": "php-symfony-mime"},
          {"reference": "php-symfony-notifier"},
          {"reference": "php-symfony-options-resolver"},
          {"reference": "php-symfony-password-hasher"},
          {"reference": "php-symfony-process"},
          {"reference": "php-symfony-property-access"},
          {"reference": "php-symfony-property-info"},
          {"reference": "php-symfony-rate-limiter"},
          {"reference": "php-symfony-remote-event"},
          {"reference": "php-symfony-routing"},
          {"reference": "php-symfony-runtime"},
          {"reference": "php-symfony-scheduler"},
          {"reference": "php-symfony-security-core"},
          {"reference": "php-symfony-security-csrf"}
        ]
      }
    ]
  },
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "symfony"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "symfony"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "symfony"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "symfony"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "symfony"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.04",
        "pkgs": [
          {"reference": "symfony"}
        ]
      }
    ]
  }
};

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');
}