Linux Distros Unpatched Vulnerability : CVE-2026-77696

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

include('compat.inc');

if (description)
{
  script_id(351167);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/30");

  script_cve_id("CVE-2026-77696");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-77696");

  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: SM2 signature generation uses non-constant-time arithmetic on secret values, forming a
    timing side-channel. Impact summary: An attacker able to measure SM2 signing times may learn information
    about the per-signature secret nonce, which over many signatures can, via a lattice / Hidden Number
    Problem attack, lead to recovery of the private key. CWE: CWE-208: Observable Timing Discrepancy
    Description: SM2 signature generation computes the signature value using variable-time BIGNUM operations
    on the secret nonce and the private key, so the time taken to produce an SM2 signature depends on these
    secret values, forming a timing side-channel. Applications performing SM2 signature generation are
    affected on all platforms. FIPS Impact: no SM2 is not a FIPS algorithm. (CVE-2026-77696)

Note that Nessus relies on the presence of the package as reported by the vendor.");
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  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-77696");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-77696");
  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:M/Au:N/C:P/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-77696");

  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:"2026/09/29");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/29");

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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");
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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": "libcrypto3-udeb"},
          {"reference": "libssl-dev"},
          {"reference": "libssl-doc"},
          {"reference": "libssl3"},
          {"reference": "libssl3-udeb"},
          {"reference": "openssl"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "libcrypto3-udeb"},
          {"reference": "libssl-dev"},
          {"reference": "libssl-doc"},
          {"reference": "libssl3-udeb"},
          {"reference": "libssl3t64"},
          {"reference": "openssl"},
          {"reference": "openssl-provider-fips"},
          {"reference": "openssl-provider-legacy"}
        ]
      }
    ]
  },
  "Ubuntu Linux-14.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14.04",
        "pkgs": [
          {"reference": "libcrypto1.0.0-udeb"},
          {"reference": "libssl-dev"},
          {"reference": "libssl-doc"},
          {"reference": "libssl1.0.0"},
          {"reference": "libssl1.0.0-dbg"},
          {"reference": "libssl1.0.0-udeb"},
          {"reference": "openssl"}
        ]
      }
    ]
  },
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "edk2"},
          {"reference": "libcrypto1.0.0-udeb"},
          {"reference": "libssl-dev"},
          {"reference": "libssl-doc"},
          {"reference": "libssl1.0.0"},
          {"reference": "libssl1.0.0-dbg"},
          {"reference": "libssl1.0.0-udeb"},
          {"reference": "nodejs"},
          {"reference": "openssl"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "edk2"},
          {"reference": "libcrypto1.0.0-udeb"},
          {"reference": "libcrypto1.1-udeb"},
          {"reference": "libssl-dev"},
          {"reference": "libssl-doc"},
          {"reference": "libssl1.0-dev"},
          {"reference": "libssl1.0.0"},
          {"reference": "libssl1.0.0-udeb"},
          {"reference": "libssl1.1"},
          {"reference": "libssl1.1-udeb"},
          {"reference": "nodejs"},
          {"reference": "openssl"},
          {"reference": "openssl1.0"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "libcrypto1.1-udeb"},
          {"reference": "libssl-dev"},
          {"reference": "libssl-doc"},
          {"reference": "libssl1.1"},
          {"reference": "libssl1.1-udeb"},
          {"reference": "openssl"},
          {"reference": "ovmf"},
          {"reference": "qemu-efi"},
          {"reference": "qemu-efi-aarch64"},
          {"reference": "qemu-efi-arm"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "nodejs"},
          {"reference": "ovmf"},
          {"reference": "ovmf-ia32"},
          {"reference": "qemu-efi"},
          {"reference": "qemu-efi-aarch64"},
          {"reference": "qemu-efi-arm"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "efi-shell-aa64"},
          {"reference": "efi-shell-arm"},
          {"reference": "efi-shell-ia32"},
          {"reference": "efi-shell-riscv64"},
          {"reference": "efi-shell-x64"},
          {"reference": "ovmf"},
          {"reference": "ovmf-ia32"},
          {"reference": "qemu-efi-aarch64"},
          {"reference": "qemu-efi-arm"},
          {"reference": "qemu-efi-riscv64"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.04",
        "pkgs": [
          {"reference": "efi-shell-aa64"},
          {"reference": "efi-shell-aa64-hwe"},
          {"reference": "efi-shell-loongarch64"},
          {"reference": "efi-shell-loongarch64-hwe"},
          {"reference": "efi-shell-riscv64"},
          {"reference": "efi-shell-riscv64-hwe"},
          {"reference": "efi-shell-x64"},
          {"reference": "efi-shell-x64-hwe"},
          {"reference": "ovmf"},
          {"reference": "ovmf-amdsev"},
          {"reference": "ovmf-amdsev-hwe"},
          {"reference": "ovmf-generic"},
          {"reference": "ovmf-generic-hwe"},
          {"reference": "ovmf-hwe"},
          {"reference": "ovmf-inteltdx"},
          {"reference": "ovmf-inteltdx-hwe"},
          {"reference": "ovmf-legacy"},
          {"reference": "ovmf-legacy-hwe"},
          {"reference": "qemu-efi-aarch64"},
          {"reference": "qemu-efi-aarch64-hwe"},
          {"reference": "qemu-efi-loongarch64"},
          {"reference": "qemu-efi-loongarch64-hwe"},
          {"reference": "qemu-efi-riscv64"},
          {"reference": "qemu-efi-riscv64-hwe"}
        ]
      }
    ]
  },
  "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": "openssl"},
          {"reference": "openssl-devel"},
          {"reference": "openssl-libs"},
          {"reference": "openssl-perl"},
          {"reference": "shim-aa64"},
          {"reference": "shim-unsigned-aarch64"},
          {"reference": "shim-unsigned-x64"},
          {"reference": "shim-x64"}
        ]
      }
    ]
  },
  "CentOS Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "AAVMF"},
          {"reference": "OVMF"},
          {"reference": "mokutil"},
          {"reference": "openssl"},
          {"reference": "openssl-devel"},
          {"reference": "openssl-libs"},
          {"reference": "openssl-perl"},
          {"reference": "openssl-static"},
          {"reference": "ovmf"},
          {"reference": "shim"},
          {"reference": "shim-ia32"},
          {"reference": "shim-signed"},
          {"reference": "shim-x64"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "AAVMF"},
          {"reference": "OVMF"},
          {"reference": "mokutil"},
          {"reference": "openssl"},
          {"reference": "openssl-devel"},
          {"reference": "openssl-libs"},
          {"reference": "openssl-perl"},
          {"reference": "openssl-static"},
          {"reference": "ovmf"},
          {"reference": "shim"},
          {"reference": "shim-ia32"},
          {"reference": "shim-signed"},
          {"reference": "shim-x64"}
        ]
      }
    ]
  },
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "compat-openssl10"},
          {"reference": "edk2"},
          {"reference": "edk2-aarch64"},
          {"reference": "edk2-ovmf"},
          {"reference": "mingw-openssl"},
          {"reference": "mingw32-openssl"},
          {"reference": "mingw64-openssl"},
          {"reference": "openssl"},
          {"reference": "openssl-devel"},
          {"reference": "openssl-libs"},
          {"reference": "openssl-perl"},
          {"reference": "openssl-static"},
          {"reference": "shim"},
          {"reference": "shim-aa64"},
          {"reference": "shim-ia32"},
          {"reference": "shim-unsigned-aarch64"},
          {"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": "mingw-openssl"},
          {"reference": "mingw32-openssl"},
          {"reference": "mingw64-openssl"},
          {"reference": "openssl"},
          {"reference": "openssl-devel"},
          {"reference": "openssl-libs"},
          {"reference": "openssl-perl"},
          {"reference": "openssl-static"},
          {"reference": "shim"},
          {"reference": "shim-aa64"},
          {"reference": "shim-ia32"},
          {"reference": "shim-unsigned-aarch64"},
          {"reference": "shim-unsigned-x64"},
          {"reference": "shim-x64"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "compat-openssl11"},
          {"reference": "edk2"},
          {"reference": "edk2-aarch64"},
          {"reference": "edk2-ovmf"},
          {"reference": "edk2-tools"},
          {"reference": "edk2-tools-doc"},
          {"reference": "openssl"},
          {"reference": "openssl-devel"},
          {"reference": "openssl-libs"},
          {"reference": "openssl-perl"},
          {"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 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_NOTE,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}