CVE-2026-59984Public exploit

Decoder crash via truncated B44 scratch allocation

Published Aug 25, 2026 · Updated Aug 25, 2026

Out-of-bounds write in OpenEXR allows attackers to crash ILP32 decoders via crafted B44-compressed scanline files. On 32-bit builds, a logical scratch size above 4 GiB truncates before allocation, while uncompress_b44_impl() uses the untrusted channel width to derive row pointers and copy data beyond the 64-byte buffer. Reachability requires an application or user to decode the file on an ILP32 build; the demonstrated consequence is a process crash, not arbitrary code execution.

CVSS severity5.5
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in OpenEXR allows attackers to crash ILP32 decoders via crafted B44-compressed scanline files. On 32-bit builds, a logical scratch size above 4 GiB truncates before allocation, while uncompress_b44_impl() uses the untrusted channel width to derive row pointers and copy data beyond the 64-byte buffer. Reachability requires an application or user to decode the file on an ILP32 build; the demonstrated consequence is a process crash, not arbitrary code execution.

The record

CVE
CVE-2026-59984
Published
Aug 25, 2026
Updated
Aug 25, 2026
Vendor
Academy Software Foundation
Product
OpenEXR
Classifications
CWE-787, T1204.002, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 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=>= 3.1.0, < 3.2.11
  2. Affected versionversion=>= 3.3.0, < 3.3.13
  3. Affected versionversion=>= 3.4.0, < 3.4.14

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Academy Software Foundation · OpenEXRversion=>= 3.1.0, < 3.2.11; version=>= 3.3.0, < 3.3.13; version=>= 3.4.0, < 3.4.14

Published CVSS scores

5.5GitHubCVSS:3.1/AV:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1204.002Malicious File
T1499.004Application 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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