CVE-2026-63638Public exploitNetwork attack vectorHinoki check available

Heap out-of-bounds write via invalid Cineon bit depth

Published Sep 18, 2026 · Updated Sep 18, 2026

Heap out-of-bounds write in OpenImageIO before 3.0.21.0, 3.1.16.0, or 3.2.0.3-beta1 allows remote attackers to corrupt memory. CineonInput::open() accepts bit depth 26 as uint32, but read_native_scanline() passes the four-byte-per-pixel buffer to libcineon, which selects an eight-byte element size. Exploitation requires a user or application to process a crafted .cin image and can overwrite heap memory or crash the process.

CVSS severity8.3
High
EPSS probability0.46%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Get started

Summary

What happened

Heap out-of-bounds write in OpenImageIO before 3.0.21.0, 3.1.16.0, or 3.2.0.3-beta1 allows remote attackers to corrupt memory. CineonInput::open() accepts bit depth 26 as uint32, but read_native_scanline() passes the four-byte-per-pixel buffer to libcineon, which selects an eight-byte element size. Exploitation requires a user or application to process a crafted .cin image and can overwrite heap memory or crash the process.

The record

CVE
CVE-2026-63638
Published
Sep 18, 2026
Updated
Sep 18, 2026
Vendor
Academy Software Foundation
Product
OpenImageIO
Classifications
CWE-787, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=< 3.0.21.0
  2. Affected versionversion=>= 3.1.0.0, < 3.1.16.0
  3. Affected versionversion=>= 3.2.0.0-dev, < 3.2.0.3-beta1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Academy Software Foundation · OpenImageIOversion=< 3.0.21.0; version=>= 3.1.0.0, < 3.1.16.0; version=>= 3.2.0.0-dev, < 3.2.0.3-beta1

Published CVSS scores

8.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

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

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Get started to see how Hinoki identifies affected software and validates exploitability in your environment.

Get started