CVE-2026-55371

OpenEXR: OpenEXRCore exr_attr_set_bytes() accepts NULL type_hint with positive hint_length

Published Aug 25, 2026 CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed

Description

OpenEXR is the reference implementation and specification for the EXR high-dynamic-range image file format, widely used in the motion picture industry. Versions 3.4.0 through 3.4.12 contain a NULL pointer dereference in the OpenEXRCore function exr_attr_set_bytes(). The public setter validates the top-level exr_attr_bytes_t value pointer but does not verify that the nested type_hint pointer is non-NULL when hint_length is greater than zero. When a caller supplies a positive hint_length together with a NULL type_hint, exr_attr_bytes_create() allocates a destination type-hint buffer and then copies from the NULL source pointer, causing a deterministic crash. The flaw is reachable through the public OpenEXRCore C API and results in a denial of service. The issue is fixed in version 3.4.13.

Analysis

Technical impact

A NULL pointer dereference occurs in the OpenEXRCore function exr_attr_set_bytes() when a caller supplies a positive hint_length together with a NULL type_hint. The function allocates a destination hint buffer and then attempts to copy data from the NULL source pointer, leading to a deterministic crash. This flaw results in a denial of service and is formally classified as CWE-20 (Improper Input Validation) and CWE-476 (NULL Pointer Dereference).

Affected Systems

The vulnerability affects AcademySoftwareFoundation’s OpenEXR library versions 3.4.0 through 3.4.12. Because the flaw is present in the public C API, any application that loads, creates, or modifies EXR byte attributes—common in motion‑picture production pipelines—could be impacted.

Risk and Exploitability

The flaw is reachable through the public OpenEXRCore API; an attacker who can provide a crafted EXR file to a UI or can invoke the API directly may trigger the crash. Based on the description, the likely attack vector is either via a malicious file or direct API misuse. The EPSS score is not available and the issue is not listed in the CISA KEV catalog, indicating no widespread exploitation yet. The CVSS score of 6.9 signifies moderate severity, but the deterministic crash makes timely patching a priority.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

AcademySoftwareFoundation

openexr

affected

Version	Status	Constraints
`>= 3.4.0, < 3.4.13`	affected	—

No data.

No data available yet.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Upgrade OpenEXR to version 3.4.13 or later, where the flaw is fixed.
Modify any code that calls exr_attr_set_bytes() to ensure a non‑NULL type_hint is supplied whenever hint_length is greater than zero, preventing accidental null inputs.
If upgrading is not immediately possible, run vulnerable applications in a sandbox or container to isolate the crash impact, or disable processing of external EXR files until a patch is applied.

Generated by OpenCVE AI on August 25, 2026 at 02:50 UTC.

Tracking

Advisories

No advisories available

Metrics

Attack Vector Local

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.167% probability within 30 days)

Exploitation none

Automatable no

Technical Impact partial

References

Link	Providers
https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-xx72-f24p-cf6r
https://nvd.nist.gov/vuln/detail/CVE-2026-55371
https://www.cve.org/CVERecord?id=CVE-2026-55371

History

Aug 26, 2026 12:15 AM Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
References		https://nvd.nist.gov/vuln/detail/CVE-2026-55371 https://www.cve.org/CVERecord?id=CVE-2026-55371
Metrics	threat_severity `None`	cvssV3_1 `{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}` threat_severity `Moderate`

Aug 25, 2026 8:30 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Aug 25, 2026 12:45 AM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		OpenEXR is the reference implementation and specification for the EXR high-dynamic-range image file format, widely used in the motion picture industry. Versions 3.4.0 through 3.4.12 contain a NULL pointer dereference in the OpenEXRCore function exr_attr_set_bytes(). The public setter validates the top-level exr_attr_bytes_t value pointer but does not verify that the nested type_hint pointer is non-NULL when hint_length is greater than zero. When a caller supplies a positive hint_length together with a NULL type_hint, exr_attr_bytes_create() allocates a destination type-hint buffer and then copies from the NULL source pointer, causing a deterministic crash. The flaw is reachable through the public OpenEXRCore C API and results in a denial of service. The issue is fixed in version 3.4.13.
Title		OpenEXR: OpenEXRCore exr_attr_set_bytes() accepts NULL type_hint with positive hint_length
Weaknesses		CWE-20 CWE-476
References		https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-xx72-f24p-cf6r
Metrics		cvssV4_0 `{'score': 6.9, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}`