Linux Distros Unpatched Vulnerability : CVE-2026-39886

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

include('compat.inc');

if (description)
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  script_id(309639);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/29");

  script_cve_id("CVE-2026-39886");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-39886");

  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.

  - OpenEXR provides the specification and reference implementation of the EXR file format, an image storage
    format for the motion picture industry. Versions 3.4.0 through 3.4.9 have a signed integer overflow
    vulnerability in OpenEXR's HTJ2K (High-Throughput JPEG 2000) decompression path. The `ht_undo_impl()`
    function in `src/lib/OpenEXRCore/internal_ht.cpp` accumulates a bytes-per-line value (`bpl`) using a
    32-bit signed integer with no overflow guard. A crafted EXR file with 16,385 FLOAT channels at the HTJ2K
    maximum width of 32,767 causes `bpl` to overflow `INT_MAX`, producing undefined behavior confirmed by
    UBSan. On an allocator-permissive host where the required ~64 GB allocation succeeds, the wrapped negative
    `bpl` value would subsequently be used as a per-scanline pointer advance, which would produce a heap out-
    of-bounds write. On a memory-constrained host, the allocation fails before `ht_undo_impl()` is entered.
    This is the second distinct integer overflow in `ht_undo_impl()`. CVE-2026-34545 addressed a different
    overflow in the same function  the `int16_t p` pixel-loop counter at line ~302 that overflows when
    iterating over channels whose `width` exceeds 32,767. The CVE-2026-34545 fix did not touch the `int bpl`
    accumulator at line 211, which is the subject of this advisory. The `bpl` accumulator was also not
    addressed by any of the 8 advisories in the 2026-04-05 v3.4.9 release batch. This finding is structurally
    identical to CVE-2026-34588 (PIZ `wcount*nx` overflow in `internal_piz.c`) and should be remediated with
    the same pattern. The CVE-2026-34588 fix did not touch `internal_ht.cpp`. Version 3.4.10 contains a
    remediation that addresses the vulnerability in `internal_ht.cpp`. (CVE-2026-39886)

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-2026-39886");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-39886");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-39886");
  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:POC/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:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-39886");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"vendor_unpatched", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/04/19");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/04/22");

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  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
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  script_dependencies("ssh_get_info2.nasl", "set_linux_os_id.nasl");
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  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/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-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "libopenexr-3-4-33"},
          {"reference": "libopenexr-dev"},
          {"reference": "libopenexr-doc"},
          {"reference": "openexr"}
        ]
      }
    ]
  },
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "libopenexr-dev"},
          {"reference": "libopenexr22"},
          {"reference": "openexr"},
          {"reference": "openexr-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "libopenexr-dev"},
          {"reference": "libopenexr22"},
          {"reference": "openexr"},
          {"reference": "openexr-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "openexr"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "openexr"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "openexr"}
        ]
      }
    ]
  },
  "Ubuntu Linux-25.10": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "25.10",
        "pkgs": [
          {"reference": "openexr"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.04",
        "pkgs": [
          {"reference": "openexr"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-10": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "10",
        "pkgs": [
          {"reference": "openexr"},
          {"reference": "openexr-devel"},
          {"reference": "openexr-libs"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "openexr"},
          {"reference": "openexr-devel"},
          {"reference": "openexr-libs"}
        ]
      }
    ]
  },
  "CentOS Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "OpenEXR"},
          {"reference": "OpenEXR-devel"},
          {"reference": "OpenEXR-libs"}
        ]
      }
    ]
  },
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "OpenEXR"},
          {"reference": "OpenEXR-devel"},
          {"reference": "OpenEXR-libs"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-6": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "6",
        "pkgs": [
          {"reference": "OpenEXR"},
          {"reference": "OpenEXR-devel"},
          {"reference": "OpenEXR-libs"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "OpenEXR"},
          {"reference": "OpenEXR-devel"},
          {"reference": "OpenEXR-libs"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "OpenEXR"},
          {"reference": "OpenEXR-devel"},
          {"reference": "OpenEXR-libs"}
        ]
      }
    ]
  }
};

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');
}