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TI-2026-26665 Aliases CVE-2026-34379

OpenEXR has a misaligned write in LossyDctDecoder_execute leading to undefined behavior (DWA/DWAB decompression)

Priority MEDIUM 64CWE-704Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · Low · High
Fix status
Partial Red Hat: 2 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

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, a misaligned memory write vulnerability exists in LossyDctDecoder_execute() in src/lib/OpenEXRCore/internal_dwa_decoder.h:749. When decoding a DWA or DWAB-compressed EXR file containing a FLOAT-type channel, the decoder performs an in-place HALF→FLOAT conversion by casting an unaligned uint8_t * row pointer to float * and writing through it. Because the row buffer may not be 4-byte aligned, this constitutes undefined behavior under the C standard and crashes immediately on architectures that enforce alignment (ARM, RISC-V, etc.). On x86 it is silently tolerated at runtime but remains exploitable via compiler optimizations that assume aligned access. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00294 22nd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial openexr (AcademySoftwareFoundation): 3.2.7, 3.3.9, 3.4.9Red Hat: 2 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

VendorProductAffected versionsFixed inStatusSource
AcademySoftwareFoundationopenexr3.2.0 to before 3.2.7; 3.3.0 to before 3.3.9; 3.4.0 to before 3.4.93.2.7, 3.3.9, 3.4.9Patch availableCNA
  • openexr VendorAcademySoftwareFoundation Affected 3.2.0 to before 3.2.7; 3.3.0 to before 3.3.9; 3.4.0 to before 3.4.9 Fixed in 3.2.7, 3.3.9, 3.4.9 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:openexr:openexr:*:*:*:*:*:*:*:*3.2.0 to before 3.2.7; 3.3.0 to before 3.3.9; 3.4.0 to before 3.4.9VulnerableAcademy Software Foundation
  • cpe:2.3:a:openexr:openexr:*:*:*:*:*:*:*:* Versions 3.2.0 to before 3.2.7; 3.3.0 to before 3.3.9; 3.4.0 to before 3.4.9 Vulnerable ·Academy Software Foundation

Remediation

  • Fix · CNA openexr (AcademySoftwareFoundation) Fixed in 3.2.7, 3.3.9, 3.4.9

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Not affected: 3 products
  • Red Hat Enterprise Linux 10
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34379

References

Exploit 1

Other 3

  • 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