Linux Distros Unpatched Vulnerability : CVE-2026-52956

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

include('compat.inc');

if (description)
{
  script_id(322700);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/06/25");

  script_cve_id("CVE-2026-52956");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-52956");

  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.

  - libceph: Fix potential out-of-bounds access in __ceph_x_decrypt() In __ceph_x_decrypt(), a part of the
    buffer p is interpreted as a ceph_x_encrypt_header, and the magic field of this struct is accessed. This
    happens without any guarantee that the buffer is large enough to hold this struct. The function parameter
    ciphertext_len represents the length of the ciphertext to decrypt and is guaranteed to be at most the
    remaining size of the allocated buffer p. However, this value is not necessarily greater than
    sizeof(ceph_x_encrypt_header). E.g., a message frame of type FRAME_TAG_AUTH_REPLY_MORE, that is just as
    long to hold the ciphertext at its end with a ciphertext_len of 8 or less, can trigger an out-of-bounds
    memory access when accessing hdr->magic. This patch fixes the issue by adding a check to ensure that the
    decrypted plaintext in the buffer is large enough to represent at least the ceph_x_encrypt_header.
    (CVE-2026-52956)

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-2026-52956");
  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: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:N/UI:N/S:U/C:H/I:H/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-2026-52956");

  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:"2026/06/24");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/06/25");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
  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:debian:debian_linux:linux");
  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-11", "Host/OS/Debian Linux-12", "Host/OS/Debian Linux-13");

  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": "btrfs-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "cdrom-core-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "ext4-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "fat-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "isofs-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "jfs-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "kernel-image-6.1.0-47-alpha-generic-di"},
          {"reference": "linux-doc"},
          {"reference": "linux-doc-6.1"},
          {"reference": "linux-headers-6.1.0"},
          {"reference": "linux-source"},
          {"reference": "linux-source-6.1"},
          {"reference": "linux-support-6.1.0"},
          {"reference": "loop-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "nic-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "nic-shared-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "nic-wireless-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "pata-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "ppp-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "scsi-core-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "scsi-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "scsi-nic-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "serial-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "usb-serial-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "xfs-modules-6.1.0-47-alpha-generic-di"}
        ]
      }
    ]
  },
  "Debian Linux-11": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "11",
        "pkgs": [
          {"reference": "bpftool"},
          {"reference": "btrfs-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "cdrom-core-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "hyperv-daemons"},
          {"reference": "kernel-image-5.10.0-32-alpha-generic-di"},
          {"reference": "libcpupower-dev"},
          {"reference": "libcpupower1"},
          {"reference": "linux-bootwrapper-5.10.0"},
          {"reference": "linux-config-5.10"},
          {"reference": "linux-cpupower"},
          {"reference": "linux-doc"},
          {"reference": "linux-doc-5.10"},
          {"reference": "linux-headers-5.10.0"},
          {"reference": "linux-kbuild-5.10"},
          {"reference": "linux-libc-dev"},
          {"reference": "linux-perf"},
          {"reference": "linux-perf-5.10"},
          {"reference": "linux-source"},
          {"reference": "linux-source-5.10"},
          {"reference": "linux-support-5.10.0"},
          {"reference": "loop-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "nic-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "nic-shared-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "nic-wireless-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "pata-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "ppp-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "scsi-core-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "scsi-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "scsi-nic-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "serial-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "usb-serial-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "usbip"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "bpftool"},
          {"reference": "hyperv-daemons"},
          {"reference": "intel-sdsi"},
          {"reference": "libcpupower-dev"},
          {"reference": "libcpupower1"},
          {"reference": "linux-bpf-dev"},
          {"reference": "linux-config-6.12"},
          {"reference": "linux-cpupower"},
          {"reference": "linux-doc"},
          {"reference": "linux-doc-6.12"},
          {"reference": "linux-headers-4kc-malta"},
          {"reference": "linux-headers-5kc-malta"},
          {"reference": "linux-headers-6.12.86+deb13-4kc-malta"},
          {"reference": "linux-headers-6.12.86+deb13-5kc-malta"},
          {"reference": "linux-headers-6.12.86+deb13-alpha-generic"},
          {"reference": "linux-headers-6.12.86+deb13-alpha-smp"},
          {"reference": "linux-headers-6.12.86+deb13-amd64"},
          {"reference": "linux-headers-6.12.86+deb13-arm64"},
          {"reference": "linux-headers-6.12.86+deb13-arm64-16k"},
          {"reference": "linux-headers-6.12.86+deb13-armmp"},
          {"reference": "linux-headers-6.12.86+deb13-armmp-lpae"},
          {"reference": "linux-headers-6.12.86+deb13-cloud-amd64"},
          {"reference": "linux-headers-6.12.86+deb13-cloud-arm64"},
          {"reference": "linux-headers-6.12.86+deb13-common"},
          {"reference": "linux-headers-6.12.86+deb13-common-rt"},
          {"reference": "linux-headers-6.12.86+deb13-loong64"},
          {"reference": "linux-headers-6.12.86+deb13-loongson-3"},
          {"reference": "linux-headers-6.12.86+deb13-m68k"},
          {"reference": "linux-headers-6.12.86+deb13-mips32r2eb"},
          {"reference": "linux-headers-6.12.86+deb13-mips32r2el"},
          {"reference": "linux-headers-6.12.86+deb13-mips64r2eb"},
          {"reference": "linux-headers-6.12.86+deb13-mips64r2el"}
        ]
      }
    ]
  }
};

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');
}