TI-2026-26664 Aliases CVE-2026-34378

OpenEXR has a signed integer overflow in generic_unpack() when parsing EXR files with crafted negative dataWindow.min.x

MEDIUM 62CWE-190Published 2026-04-06 · Updated 2026-04-07

Key facts

Attack vector: Network
Privileges required: None
User interaction: Required
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Partial Red Hat: 5 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-190 and the CVSS impact.

Summary

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.4.0 to before 3.4.9, a missing bounds check on the dataWindow attribute in EXR file headers allows an attacker to trigger a signed integer overflow in generic_unpack(). By setting dataWindow.min.x to a large negative value, OpenEXRCore computes an enormous image width, which is later used in a signed integer multiplication that overflows, causing the process to terminate with SIGILL via UBSan. This vulnerability is fixed in 3.4.9.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00272 19th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Partial openexr (AcademySoftwareFoundation): 3.4.9Red Hat: 5 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
AcademySoftwareFoundation	openexr	3.4.0 to before 3.4.9	3.4.9	Patch available	CNA

openexr VendorAcademySoftwareFoundation Affected 3.4.0 to before 3.4.9 Fixed in 3.4.9 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:openexr:openexr::::::::	3.4.0 to before 3.4.9	Vulnerable	Academy Software Foundation

cpe:2.3:a:openexr:openexr:*:*:*:*:*:*:*:* Versions 3.4.0 to before 3.4.9 Vulnerable ·Academy Software Foundation

Remediation

Fix · CNA openexr (AcademySoftwareFoundation) Fixed in 3.4.9

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 6	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 7	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 8	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 9	Affected	No fix yet: Fix deferred

Timeline

2026-10-02 Threatist record created from CVE-2026-34378

References

Exploit 1

https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-v76p-4qvv-vh4g

Other 1

https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.9

TI-2026-30739 OpenColorIO vulnerable to stack buffer overflow via unbounded `sscanf %s` in Spi3D (.spi3d) LUT parser CVSS 4.0HIGH 8.4
TI-2026-38605 OpenEXR: Unhandled assert abort in HTJ2K decoder via crafted QCD marker (DoS) CVSS 4.0HIGH 7.1
TI-2026-48281 OpenEXR: Heap out-of-bounds write in exrmultiview with subsampled channel union CVSS 3.1HIGH 7.1
TI-2026-48279 OpenEXR: Heap buffer overflow in PyOpenEXR from literal/prefixed RGB channel name collision CVSS 3.1HIGH 7.1
TI-2026-42768 OpenEXR: Heap OOB read in SampleCountChannel row when using nonzero dataWindow CVSS 3.1HIGH 7.1
TI-2026-42338 OpenEXR: Out-of-bounds read in DeepImageChannel::row() for non-zero dataWindow origin CVSS 3.1HIGH 7.1

See all 26 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences