OpenEXR: HTJ2K SIZ image-offset gap stack buffer overflow (CVE-2026-68516) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-68516

OpenEXR: HTJ2K SIZ image-offset gap stack buffer overflow

Answer in brief

CVE-2026-68516 records a Unknown severity vulnerability in OpenEXR: HTJ2K SIZ image-offset gap stack buffer overflow. 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 24, 2026Updated Aug 24, 2026Source checked Aug 25, 2026First seen by HOL Aug 24, 2026Material review Aug 24, 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	>= 3.4.0, < 3.4.14	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 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 24, 2026

Sources and claim methodology

Upstream source description

OpenEXR is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. From version 3.4.0 through 3.4.13, a crafted HTJ2K-compressed EXR can crash OpenEXR during normal decode. An HTJ2K-compressed EXR whose JPEG 2000 SIZ fields place the first tile outside the visible image can reach invalid tile and codeblock geometry in the vendored OpenJPH AVX2 decoder, causing a stack out-of-bounds write and denial of service. OpenEXR's HTJ2K path validates the decoded codestream dimensions against the EXR chunk size, but it does not reject SIZ image-offset/tile-grid geometry where the first tile does not intersect the image. This issue is fixed in version 3.4.14.

Quoted source text, attributed separately from HOL analysis.