OpenEXR: OpenEXRUtil SampleCountChannel row setter heap has an out-of-bounds write vulnerability (CVE-2026-55059) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-55059

OpenEXR: OpenEXRUtil SampleCountChannel row setter heap has an out-of-bounds write vulnerability

Answer in brief

CVE-2026-55059 records a Unknown severity vulnerability in OpenEXR: OpenEXRUtil SampleCountChannel row setter heap has an out-of-bounds write vulnerability. The current sources do not mark it as known exploited. The current feed maps AcademySoftwareFoundation/openexr (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 25, 2026Updated Aug 25, 2026Source checked Aug 25, 2026First seen by HOL Aug 25, 2026Material review Aug 25, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps AcademySoftwareFoundation/openexr (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
AcademySoftwareFoundation/openexrgeneric	< 3.2.10 \|\| >= 3.3.0, < 3.3.12 \|\| >= 3.4.0, < 3.4.13	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for AcademySoftwareFoundation/openexr.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 25, 2026

Sources and claim methodology

GitHub security advisorygithub.com

Upstream source description

OpenEXR is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. Versions prior to 3.2.10, 3.3.12 and 3.4.13 contain a heap out-of-bounds write in Imf_4_0::SampleCountChannel::set(int r, unsigned int newNumSamples[]). The row-based sample-count setter computes the target Y coordinate with dataWindow.min.x instead of dataWindow.min.y. For a valid deep image data window where min.x != min.y, a valid row index can be translated into an invalid Y coordinate, causing writes before the allocated _numSamples buffer. The vulnerability is reachable through the public OpenEXRUtil DeepImage API and can lead to heap corruption and process crashes. This issue has been fixed in versions 3.2.10, 3.3.12 and 3.4.13.

Quoted source text, attributed separately from HOL analysis.