CVE-2026-34588

Openexr buffer overflow

7.8 HIGHPublic exploitEPSS 0.57%

Published6 Apr 2026

Description

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.1.0 to before 3.2.7, 3.3.9, and 3.4.9, internal_exr_undo_piz() advances the working wavelet pointer with signed 32-bit arithmetic. Because nx, ny, and wcount are int, a crafted EXR file can make this product overflow and wrap. The next channel then decodes from an incorrect address. The wavelet decode path operates in place, so this yields both out-of-bounds reads and out-of-bounds writes. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9.

CVSS 3.1 breakdown

Attack vectorLocal

Attack complexityLow

Privileges requiredLow

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

Openexr≥ 3.1.0 < 3.2.7 · ≥ 3.3.0 < 3.3.9 · ≥ 3.4.0 < 3.4.9

Remediation

Fixed in

Openexr≥ 3.2.7

Patch & vendor advisories

https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-588r-cr5c-w6hf

References

and 10 more references

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-34588 being actively exploited?

CVE-2026-34588 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.57%.

How severe is CVE-2026-34588?

CVE-2026-34588 has a CVSS 3.1 base score of 7.8, rated high. EPSS estimates a 0.57% probability of exploitation.

Which products are affected by CVE-2026-34588?

Affected products include Openexr.

How do I fix CVE-2026-34588?

Upgrade affected software to a fixed version, for example Openexr 3.2.7 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-34588 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.