Python Library OpenEXR 3.3.x < 3.3.7 / 3.4.x < 3.4.5 Heap Buffer Overflow (OOB Read)

medium Nessus Plugin ID 301139

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Synopsis

A Python library installed on the remote host is affected by a heap buffer overflow vulnerability.

Description

The version of the OpenEXR Python package installed on the remote host is 3.3.x prior to 3.3.7 or 3.4.x prior to 3.4.5. It is, therefore, affected by a heap buffer overflow vulnerability:

- A heap-buffer-overflow (out-of-bounds read) occurs in the istream_nonparallel_read function in ImfContextInit.cpp when parsing a malformed EXR file through a memory-mapped IStream. A signed integer subtraction produces a negative value that is implicitly converted to size_t, resulting in a massive length being passed to memcpy. (CVE-2026-26981)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade to OpenEXR version 3.3.7, 3.4.5 or later.

Plugin Details

Severity: Medium

ID: 301139

File Name: python_openexr_CVE-2026-26981.nasl

Version: 1.1

Type: local

Agent: windows, macosx, unix

Family: Misc.

Published: 3/6/2026

Updated: 3/6/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: High

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

CVSS Score Source: CVE-2026-26981

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Vulnerability Information

CPE: cpe:/a:academysoftwarefoundation:openexr

Patch Publication Date: 2/21/2026

Vulnerability Publication Date: 2/21/2026

Reference Information

CVE: CVE-2026-26981

IAVA: 2026-A-0206

Detections

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