Linux Distros Unpatched Vulnerability : CVE-2026-28386

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

include('compat.inc');

if (description)
{
  script_id(305211);
  script_version("1.11");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/05/27");

  script_cve_id("CVE-2026-28386");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-28386");

  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.

  - Issue summary: Applications using AES-CFB128 encryption or decryption on systems with AVX-512 and VAES
    support can trigger an out-of-bounds read of up to 15 bytes when processing partial cipher blocks. Impact
    summary: This out-of-bounds read may trigger a crash which leads to Denial of Service for an application
    if the input buffer ends at a memory page boundary and the following page is unmapped. There is no
    information disclosure as the over-read bytes are not written to output. The vulnerable code path is only
    reached when processing partial blocks (when a previous call left an incomplete block and the current call
    provides fewer bytes than needed to complete it). Additionally, the input buffer must be positioned at a
    page boundary with the following page unmapped. CFB mode is not used in TLS/DTLS protocols, which use CBC,
    GCM, CCM, or ChaCha20-Poly1305 instead. For these reasons the issue was assessed as Low severity according
    to our Security Policy. Only x86-64 systems with AVX-512 and VAES instruction support are affected. Other
    architectures and systems without VAES support use different code paths that are not affected. OpenSSL
    FIPS module in 3.6 version is affected by this issue. (CVE-2026-28386)

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-2026-28386");
  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:N/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: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-2026-28386");

  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:"2026/03/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/04/07");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:7");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:6");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7");
  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:AAVMF");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:OVMF");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:compat-openssl10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:edk2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:edk2-aarch64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:edk2-ovmf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:edk2-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:edk2-tools-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:mingw32-openssl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:mingw64-openssl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:mokutil");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:openssl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:openssl-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:openssl-perl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:openssl-static");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:ovmf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:shim");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:shim-aa64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:shim-ia32");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:shim-unsigned-aarch64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:shim-unsigned-x64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:shim-x64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:AAVMF");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:OVMF");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:compat-openssl10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:edk2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:edk2-aarch64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:edk2-ovmf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:edk2-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:edk2-tools-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:mingw32-openssl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:mingw64-openssl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:mokutil");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:openssl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:openssl-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:openssl-perl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:openssl-static");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:ovmf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:shim");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:shim-aa64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:shim-ia32");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:shim-unsigned-aarch64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:shim-unsigned-x64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:shim-x64");
  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/CentOS Linux-7", "Host/OS/CentOS Linux-8", "Host/OS/Red Hat Enterprise Linux-10", "Host/OS/Red Hat Enterprise Linux-6", "Host/OS/Red Hat Enterprise Linux-7", "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": "edk2"},
          {"reference": "edk2-aarch64"},
          {"reference": "edk2-ovmf"},
          {"reference": "edk2-tools"},
          {"reference": "edk2-tools-doc"},
          {"reference": "mokutil"},
          {"reference": "shim-aa64"},
          {"reference": "shim-unsigned-aarch64"},
          {"reference": "shim-unsigned-x64"},
          {"reference": "shim-x64"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-6": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "6",
        "pkgs": [
          {"reference": "openssl"},
          {"reference": "openssl-devel"},
          {"reference": "openssl-perl"},
          {"reference": "openssl-static"}
        ]
      }
    ]
  },
  "CentOS Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "AAVMF"},
          {"reference": "OVMF"},
          {"reference": "ovmf"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "AAVMF"},
          {"reference": "OVMF"},
          {"reference": "ovmf"}
        ]
      }
    ]
  },
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "compat-openssl10"},
          {"reference": "edk2"},
          {"reference": "edk2-aarch64"},
          {"reference": "edk2-ovmf"},
          {"reference": "mingw32-openssl"},
          {"reference": "mingw64-openssl"},
          {"reference": "shim"},
          {"reference": "shim-aa64"},
          {"reference": "shim-ia32"},
          {"reference": "shim-unsigned-x64"},
          {"reference": "shim-x64"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "compat-openssl10"},
          {"reference": "edk2"},
          {"reference": "edk2-aarch64"},
          {"reference": "edk2-ovmf"},
          {"reference": "mingw32-openssl"},
          {"reference": "mingw64-openssl"},
          {"reference": "shim"},
          {"reference": "shim-aa64"},
          {"reference": "shim-ia32"},
          {"reference": "shim-unsigned-x64"},
          {"reference": "shim-x64"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "edk2"},
          {"reference": "edk2-aarch64"},
          {"reference": "edk2-ovmf"},
          {"reference": "edk2-tools"},
          {"reference": "edk2-tools-doc"},
          {"reference": "shim"},
          {"reference": "shim-aa64"},
          {"reference": "shim-unsigned-aarch64"},
          {"reference": "shim-unsigned-x64"},
          {"reference": "shim-x64"}
        ]
      }
    ]
  }
};

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');
}