Linux Distros Unpatched Vulnerability : CVE-2026-15811

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

include('compat.inc');

if (description)
{
  script_id(328674);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/22");

  script_cve_id("CVE-2026-15811");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-15811");

  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.

  - A vulnerability was found in kronosnet's (version <=1.34) cryptographic configuration management. The
    framework does not correctly zero-out or wipe sensitive memory segments after executing changes to its
    cryptographic configuration. This omission leaves raw encryption keys resident in memory after the
    associated structures are freed. A local attacker capable of leveraging memory disclosure techniques could
    exploit this flaw to retrieve the active encryption key, allowing them to decrypt cluster network
    communications or inject malicious packets to cause severe high-availability cluster instability.
    (CVE-2026-15811)

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-2026-15811");
  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:L/AC:H/Au:S/C:C/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:L/AC:H/PR:L/UI:N/S:U/C:H/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-2026-15811");

  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:"2026/07/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/07/21");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:8");
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  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:9");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:libknet1");
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  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/CentOS Linux-8", "Host/OS/Red Hat Enterprise Linux-10", "Host/OS/Red Hat Enterprise Linux-8", "Host/OS/Red Hat Enterprise Linux-9");

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

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Red Hat Enterprise Linux-10": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "10",
        "pkgs": [
          {"reference": "libknet1"},
          {"reference": "libknet1-compress-bzip2-plugin"},
          {"reference": "libknet1-compress-lz4-plugin"},
          {"reference": "libknet1-compress-lzma-plugin"},
          {"reference": "libknet1-compress-lzo2-plugin"},
          {"reference": "libknet1-compress-plugins-all"},
          {"reference": "libknet1-compress-zlib-plugin"},
          {"reference": "libknet1-compress-zstd-plugin"},
          {"reference": "libknet1-crypto-nss-plugin"},
          {"reference": "libknet1-crypto-openssl-plugin"},
          {"reference": "libknet1-crypto-plugins-all"},
          {"reference": "libknet1-devel"},
          {"reference": "libknet1-plugins-all"},
          {"reference": "libnozzle1"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "libknet1"},
          {"reference": "libknet1-compress-bzip2-plugin"},
          {"reference": "libknet1-compress-lz4-plugin"},
          {"reference": "libknet1-compress-lzma-plugin"},
          {"reference": "libknet1-compress-lzo2-plugin"},
          {"reference": "libknet1-compress-plugins-all"},
          {"reference": "libknet1-compress-zlib-plugin"},
          {"reference": "libknet1-compress-zstd-plugin"},
          {"reference": "libknet1-crypto-nss-plugin"},
          {"reference": "libknet1-crypto-openssl-plugin"},
          {"reference": "libknet1-crypto-plugins-all"},
          {"reference": "libknet1-devel"},
          {"reference": "libknet1-plugins-all"},
          {"reference": "libnozzle1"}
        ]
      }
    ]
  },
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "libknet1"},
          {"reference": "libknet1-compress-bzip2-plugin"},
          {"reference": "libknet1-compress-lz4-plugin"},
          {"reference": "libknet1-compress-lzma-plugin"},
          {"reference": "libknet1-compress-lzo2-plugin"},
          {"reference": "libknet1-compress-plugins-all"},
          {"reference": "libknet1-compress-zlib-plugin"},
          {"reference": "libknet1-crypto-nss-plugin"},
          {"reference": "libknet1-crypto-openssl-plugin"},
          {"reference": "libknet1-crypto-plugins-all"},
          {"reference": "libknet1-devel"},
          {"reference": "libknet1-plugins-all"},
          {"reference": "libnozzle1"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "libknet1"},
          {"reference": "libknet1-compress-bzip2-plugin"},
          {"reference": "libknet1-compress-lz4-plugin"},
          {"reference": "libknet1-compress-lzma-plugin"},
          {"reference": "libknet1-compress-lzo2-plugin"},
          {"reference": "libknet1-compress-plugins-all"},
          {"reference": "libknet1-compress-zlib-plugin"},
          {"reference": "libknet1-crypto-nss-plugin"},
          {"reference": "libknet1-crypto-openssl-plugin"},
          {"reference": "libknet1-crypto-plugins-all"},
          {"reference": "libknet1-devel"},
          {"reference": "libknet1-plugins-all"},
          {"reference": "libnozzle1"}
        ]
      }
    ]
  }
};

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');
}