CVE-2026-26981Public exploitNetwork attack vector

Application crash via wrapped memory-mapped read length

Published Feb 24, 2026 · Updated Feb 24, 2026

Heap-buffer overflow in OpenEXR 3.3.0 through 3.3.6 and 3.4.0 through 3.4.4 allows attackers to crash an application with a crafted EXR file. The istream_nonparallel_read function subtracts nend rather than nread from the stream size, converts the negative length to size_t, and passes it to memcpy. Exploitation requires an application to open the file through a memory-mapped IStream, causing an immediate process crash without reported data disclosure or modification.

CVSS severity6.5
Medium
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-buffer overflow in OpenEXR 3.3.0 through 3.3.6 and 3.4.0 through 3.4.4 allows attackers to crash an application with a crafted EXR file. The istream_nonparallel_read function subtracts nend rather than nread from the stream size, converts the negative length to size_t, and passes it to memcpy. Exploitation requires an application to open the file through a memory-mapped IStream, causing an immediate process crash without reported data disclosure or modification.

The record

CVE
CVE-2026-26981
Published
Feb 24, 2026
Updated
Feb 24, 2026
Vendor
Academy Software Foundation
Product
OpenEXR
Classifications
CWE-195, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 24, 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=>= 3.3.0, < 3.3.7
  2. Affected versionversion=>= 3.4.0, < 3.4.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Academy Software Foundation · OpenEXRversion=>= 3.3.0, < 3.3.7; version=>= 3.4.0, < 3.4.5

Published CVSS scores

6.5GitHub Advisory DatabaseCVSS: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-195Signed to Unsigned Conversion Error
T1204.002Malicious File

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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