CVE-2026-63638: Memory Corruption (CVSS 8.3)

Description

OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant to VFX / animation. Prior to 3.0.21.0, 3.1.16.0, and 3.2.0.3-beta1, A crafted cineon image can declare unsupported component bit depth 26. cineoninput::open() maps it to a 32-bit imagespec, but libcineon maps the unsupported depth to an 8-byte value, so cineoninput::read_native_scanline() causes attacker-controlled data to be written beyond the 4-byte-per-pixel caller buffer, resulting in a heap out-of-bounds write and memory corruption. The affected implementation is identified by src/cineon.imageio/cineoninput.cpp, CineonInput::open(), CineonInput::read_native_scanline(), ComponentDataSize(), bit depth 26, and ImageSpec, which define the relevant source path, functions, state, and trigger. This issue is fixed in versions 3.0.21.0, 3.1.16.0, and 3.2.0.3-beta1.

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CVSS v3.1 Score

8.3

HIGH

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

EPSS — Exploit Prediction

0.0046

Probability of exploitation

0.38%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-787 Out-of-bounds Write

References

Other References

https://github.com/AcademySoftwareFoundation/OpenImageIO/commit/6f2b2e85b3b3933ccc5a46303d5535f99bfa39fb https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/5283 https://github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.0.21.0 https://github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.1.16.0 https://github.com/AcademySoftwareFoundation/OpenImageIO/security/advisories/GHSA-9hxv-jvgr-3x8g https://github.com/AcademySoftwareFoundation/OpenImageIO/security/advisories/GHSA-9hxv-jvgr-3x8g

Frequently Asked Questions

What is CVE-2026-63638? +

OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant to VFX / animation. Prior to 3.0.21.0, 3.1.16.0, and 3.2.0.3-beta1, A crafted cineon image can declare unsupported component bit depth 26. cineoninput::open() maps it to a 32-bit imagespec, but libcineon maps the unsupported depth to an 8-byte value, so cineoninput::read_native_scanline() causes attacker-controlled data to be written beyond the 4-byte-per-pixel caller buffer, resulting in a heap out-of-bounds write and memory corruption. The affected implementation is identified by src/cineon.imageio/cineoninput.cpp, CineonInput::open(), CineonInput::read_native_scanline(), ComponentDataSize(), bit depth 26, and ImageSpec, which define the relevant source path, functions, state, and trigger. This issue is fixed in versions 3.0.21.0, 3.1.16.0, and 3.2.0.3-beta1. It has a CVSS v3.1 base score of 8.3 (HIGH).

How severe is CVE-2026-63638? +

CVE-2026-63638 has a CVSS v3.1 score of 8.3 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0046, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-63638? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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