Vulnerability · Published Aug 24, 2026 · Assigned by GitHub_M

CVE-2026-68516OpenEXR: HTJ2K SIZ image-offset gap stack buffer overflow

Medium 6.5

In plain English

A medium-severity out-of-bounds write in openexr from AcademySoftwareFoundation. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.5%top 60.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12openexrno fix listedDEBIAN-CVE-2026-68516
Debian:13openexrno fix listedDEBIAN-CVE-2026-68516
Debian:14openexr3.4.14-0.1DEBIAN-CVE-2026-68516
Ubuntu:26.10openexrno fix listedUBUNTU-CVE-2026-68516

Affected products (as reported)

VendorProductVersions
AcademySoftwareFoundation openexr >= 3.4.0, < 3.4.14

Weakness: CWE-787, CWE-121 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References