CVE-2026-68516

OpenEXR: HTJ2K SIZ image-offset gap stack buffer overflow

Published Aug 24, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
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.

Analysis

AI-generated

Technical impact

A crafted HTJ2K‑compressed EXR can cause the OpenEXR library to crash by writing beyond the bounds of a stack buffer in its vendored OpenJPH AVX2 decoder. The flaw originates from allowing SIZ fields with image‑offset or tile‑grid geometry that places the first tile outside the visible image area. The resulting out‑of‑bounds write leads to a crash or denial of service when the library decodes such a file.

Affected Systems

The vulnerability impacts the AcademySoftwareFoundation OpenEXR library versions 3.4.0 through 3.4.13. These releases perform HTJ2K decoding but fail to reject SIZ configurations that do not intersect the image, ultimately triggering the stack overflow. Versions 3.4.14 and later contain the fix and are not affected.

Risk and Exploitability

The CVSS score of 6.5 indicates a moderate severity. EPSS data is unavailable, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. The likely attack vector is the delivery of a malicious HTJ2K‑compressed EXR file to any application that uses the affected OpenEXR library. Exploitation requires decoding the crafted file, which most commonly occurs in media handling or rendering pipelines. Because the flaw only triggers a crash, there is no evidence of remote code execution from the current description.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade the OpenEXR library to version 3.4.14 or later to apply the patch that rejects invalid HTJ2K SIZ geometry.
  • If an upgrade cannot be performed immediately, restrict or disable HTJ2K decoding for untrusted input, or sandbox the decoding process to contain a crash.
  • Monitor application logs for stack overflow or segmentation fault events during image processing and investigate any anomalies for potential exploitation.

Generated by OpenCVE AI on August 24, 2026 at 23:13 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title OpenEXR: HTJ2K SIZ image-offset gap stack buffer overflow
Weaknesses CWE-121
CWE-787
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

Subscriptions

No data.

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 25, 2026, 2:25 PM
Reserved
Jul 30, 2026, 4:19 PM
Status
Deferred
Published
Aug 24, 2026, 10:17 PM
Modified
Oct 12, 2026, 3:10 PM
Severity
Moderate
Public date
Aug 24, 2026, 10:08 PM