CVE-2026-34545
From version 3.4.0 to before version 3.4.7, an attacker providing a crafted .exr file with HTJ2K compression and a channel width of 32768 can write controlled data beyond the output heap buffer in any application that decodes EXR images.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.61%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From version 3.4.0 to before version 3.4.7, an attacker providing a crafted .exr file with HTJ2K compression and a channel width of 32768 can write controlled data beyond the output heap buffer in any application that decodes EXR images. The write primitive is 2 bytes per overflow iteration or 4 bytes (by another path), repeating for each additional pixel past the overflow point. In this context, a heap write overflow can lead to remote code execution on systems. This issue has been patched in version 3.4.7.
- CVSS 4.0
- 8.4 HIGHCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.61% probability · 47th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-122, CWE-190, CWE-1284
- Affected
- openexr/openexr
- Source
- security-advisories@github.com
References
- https://github.com/AcademySoftwareFoundation/openexr/commit/3827998f5c041d6a94c6af24bbb363daa669e4b3Patch
- https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.7Product, Release Notes
- https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-ghfj-fx47-wg97Exploit, Vendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-34545
- https://bugzilla.redhat.com/show_bug.cgi?id=2454139
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34545.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.