Linux Distros Unpatched Vulnerability : CVE-2026-6104

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

include('compat.inc');

if (description)
{
  script_id(313254);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/05/27");

  script_cve_id("CVE-2026-6104");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-6104");

  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 PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded
    NUL byte is passed to mb_convert_encoding() or related mbstring functions, the code incorrectly assumes
    that when strncasecmp() returns 0 it means the strings have the same length. This can lead to out-of-
    bounds read of global memory, potentially causing a crash or information disclosure or crash. Affected
    functions include mb_convert_encoding(), mb_detect_encoding(), mb_convert_variables(), and
    mb_detect_order(), as well as the mbstring.detect_order and mbstring.http_output INI settings.
    (CVE-2026-6104)

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-2026-6104");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-6104");
  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: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:N/UI:N/S:U/C:H/I:N/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:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:L");
  script_set_attribute(attribute:"cvss4_supplemental", value:"CVSS:4.0/RE:M/U:Amber");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-6104");

  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:"plugin_publication_date", value:"2026/05/08");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:25.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:php8.4");
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  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:php8.4-gd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:php8.4-gmp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:php8.4-intl");
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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/Red Hat Enterprise Linux-10", "Host/OS/Ubuntu Linux-25.10");

  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")) && empty_or_null(get_one_kb_item("Host/RedHat/rpm-list"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Ubuntu Linux-25.10": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "25.10",
        "pkgs": [
          {"reference": "libapache2-mod-php8.4"},
          {"reference": "libphp8.4-embed"},
          {"reference": "php8.4"},
          {"reference": "php8.4-bcmath"},
          {"reference": "php8.4-bz2"},
          {"reference": "php8.4-cgi"},
          {"reference": "php8.4-cli"},
          {"reference": "php8.4-common"},
          {"reference": "php8.4-curl"},
          {"reference": "php8.4-dba"},
          {"reference": "php8.4-dev"},
          {"reference": "php8.4-enchant"},
          {"reference": "php8.4-fpm"},
          {"reference": "php8.4-gd"},
          {"reference": "php8.4-gmp"},
          {"reference": "php8.4-interbase"},
          {"reference": "php8.4-intl"},
          {"reference": "php8.4-ldap"},
          {"reference": "php8.4-mbstring"},
          {"reference": "php8.4-mysql"},
          {"reference": "php8.4-odbc"},
          {"reference": "php8.4-opcache"},
          {"reference": "php8.4-pgsql"},
          {"reference": "php8.4-phpdbg"},
          {"reference": "php8.4-readline"},
          {"reference": "php8.4-snmp"},
          {"reference": "php8.4-soap"},
          {"reference": "php8.4-sqlite3"},
          {"reference": "php8.4-sybase"},
          {"reference": "php8.4-tidy"},
          {"reference": "php8.4-xml"},
          {"reference": "php8.4-xsl"},
          {"reference": "php8.4-zip"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-10": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "10",
        "pkgs": [
          {"reference": "php8.4"},
          {"reference": "php8.4-bcmath"},
          {"reference": "php8.4-cli"},
          {"reference": "php8.4-common"},
          {"reference": "php8.4-dba"},
          {"reference": "php8.4-dbg"},
          {"reference": "php8.4-devel"},
          {"reference": "php8.4-embedded"},
          {"reference": "php8.4-enchant"},
          {"reference": "php8.4-ffi"},
          {"reference": "php8.4-fpm"},
          {"reference": "php8.4-gd"},
          {"reference": "php8.4-gmp"},
          {"reference": "php8.4-intl"},
          {"reference": "php8.4-ldap"},
          {"reference": "php8.4-mbstring"},
          {"reference": "php8.4-mysqlnd"},
          {"reference": "php8.4-odbc"},
          {"reference": "php8.4-opcache"},
          {"reference": "php8.4-pdo"},
          {"reference": "php8.4-pgsql"},
          {"reference": "php8.4-process"},
          {"reference": "php8.4-snmp"},
          {"reference": "php8.4-soap"},
          {"reference": "php8.4-xml"}
        ]
      }
    ]
  }
};

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 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');
}