CVE-2026-34378Public exploitNetwork attack vector

Application crash via unchecked EXR image width

Published Apr 6, 2026 · Updated Apr 6, 2026

Integer overflow in OpenEXR 3.4.0 through 3.4.8 allows remote attackers to crash EXR-processing applications via a crafted file. OpenEXRCore accepts a large negative dataWindow.min.x without a bounds check, computes an enormous width, and overflows w * bpc in generic_unpack(). Exploitation requires an application to parse the supplied file; the bounded consequence is termination of that process, not data disclosure or modification.

CVSS severity6.5
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in OpenEXR 3.4.0 through 3.4.8 allows remote attackers to crash EXR-processing applications via a crafted file. OpenEXRCore accepts a large negative dataWindow.min.x without a bounds check, computes an enormous width, and overflows w * bpc in generic_unpack(). Exploitation requires an application to parse the supplied file; the bounded consequence is termination of that process, not data disclosure or modification.

The record

CVE
CVE-2026-34378
Published
Apr 6, 2026
Updated
Apr 6, 2026
Vendor
Academy Software Foundation
Product
OpenEXR
Classifications
CWE-20, CWE-190, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 3.4.0, < 3.4.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Academy Software Foundation · OpenEXRversion=>= 3.4.0, < 3.4.9

Published CVSS scores

6.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
CWE-190Integer Overflow or Wraparound
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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