CVE-2026-34589
For a large enough width, the calculation overflows and later decoder stores operate on a wrapped pointer outside the allocated rowBlock backing store.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.42%). 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 3.2.0 to before 3.2.7, 3.3.9, and 3.4.9, the DWA lossy decoder constructs temporary per-component block pointers using signed 32-bit arithmetic. For a large enough width, the calculation overflows and later decoder stores operate on a wrapped pointer outside the allocated rowBlock backing store. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9.
- 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
- 0.42% probability · 35th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-190, CWE-787
- Affected
- openexr/openexr
- Source
- security-advisories@github.com
References
- https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.2.7Product, Release Notes
- https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.3.9Product, Release Notes
- https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.9Product, Release Notes
- https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-p8xc-w3q4-h64xExploit, Vendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-34589
- https://bugzilla.redhat.com/show_bug.cgi?id=2455411
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34589.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.