CVE-2026-68516: OpenEXR: HTJ2K SIZ image-offset gap stack buffer overflow
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
OpenEXRto a version that resolves this vulnerability.Fixed in 3.4.14
Event History
Frequently Asked Questions
Which deployments are affected?
OpenEXR versions 3.4.0 through 3.4.13 are affected when they decode HTJ2K-compressed EXR content. Deployments that do not process such files are not described as reaching the vulnerable path.
What does an attacker need to do to trigger the issue?
An attacker needs to provide a crafted HTJ2K-compressed EXR file with JPEG 2000 SIZ fields that place the first tile outside the visible image. User interaction is required to cause the vulnerable application to decode the file.
What is the practical impact?
The malformed file can cause a stack out-of-bounds write in the vendored OpenJPH AVX2 decoder during decoding, resulting in a crash and denial of service. The provided information does not claim confidentiality or integrity impact.
How should affected systems be remediated?
Upgrade OpenEXR to version 3.4.14, which fixes the issue. If upgrading cannot happen immediately, avoid decoding untrusted HTJ2K-compressed EXR files.