Buffer overflow in Academysoftwarefoundation Openimageio
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (40.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 40.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Academysoftwarefoundation Openimageio — versions < 3.0.21.0, >= 3.1.0.0, < 3.1.16.0, >= 3.2.0.0-dev, < 3.2.0.3-beta1
- Openimageio — versions 3.2.0.0, 3.2.0.2
Weakness classification (CWE)
References
- github.com/AcademySoftwareFoundation/OpenImageIO/security/advisories/GHSA-9hxv-… (Exploit, Mitigation, Vendor Advisory)
- github.com/AcademySoftwareFoundation/OpenImageIO/pull/5283 (Patch, Issue Tracking)
- github.com/AcademySoftwareFoundation/OpenImageIO/commit/6f2b2e85b3b3933ccc5a463… (Patch)
- github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.0.21.0 (Release Notes)
- github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.1.16.0 (Release Notes)
Frequently asked questions
- What is CVE-2026-63638?
- CVE-2026-63638 is a high-severity vulnerability in Academysoftwarefoundation Openimageio, classified under Out-of-bounds Write. CVSS score: 8.3/10. Published 2026-09-18.
- How severe is CVE-2026-63638?
- High severity. CVSS v3 base score is 8.3 out of 10.