CVE-2026-59956: OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant

Routine

MEDIUM 6.1UPGRADE

CVE-2026-59956 is a medium-severity flaw (CVSS 6.1) affecting openimageio. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant to VFX / animation. Prior to 3.0.20.0, 3.1.15.0, and 3.2.0.3-beta1, An uncompressed 16-bit iff image with a z-buffer makes iffinput::readimg() allocate a temporary scanline from m_header.rgba_count but copy from it using m_header.pixel_bytes(), whose stride also includes z-buffer bytes. the oversized memcpy reads beyond the temporary heap

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 90%)
CISA exploited list	No
Weakness	CWE-125
Published	2026-09-18
Last modified	2026-09-29

Publisher (CNA): GitHub, Inc. · Vendor: openimageio

Last updated 2026-09-29 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-18 16:17 UTCPublished CVE record published
2026-09-29 18:56 UTCUpdated Record last modified

openimageio openimageio UPGRADE

Affected: < 3.0.20.0 · >= 3.1.0.0 and <= 3.1.15.0 · 3.2.0.0 dev · 3.2.0.2 dev

Fixed in: 3.0.20.0

Safe to downgrade to: a release before 3.1.0.0

1. Check installed version

apt-cache policy openimageio || rpm -q openimageio || openimageio --version

2. UPGRADE to 3.0.20.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade openimageio

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade openimageio

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.1.0.0 (Debian / Ubuntu)

apt-cache madison openimageio sudo apt install openimageio=<VERSION_BEFORE_3.1.0.0> sudo apt-mark hold openimageio

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list openimageio sudo dnf downgrade openimageio-<VERSION_BEFORE_3.1.0.0> sudo dnf versionlock add openimageio

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-59956?

openimageio: upgrade to 3.0.20.0. Exact commands for each OS are on this page.

Is CVE-2026-59956 being exploited?

CVE-2026-59956 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-59956 affect?

CVE-2026-59956 affects openimageio. Severity is medium (CVSS 6.1). OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant to VFX / animation. Prior to 3.0.20.0, 3.1.15.0, and 3.2.0.3-beta1, An uncompressed 16-bit iff image with a z-buffer makes iffinpu

How urgent is CVE-2026-59956?

Priority 29/100. Public exploit reference

Related CVEs

CVE-2026-43908 HIGH 8.8 UPGRADE OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant
CVE-2026-43909 HIGH 8.8 UPGRADE OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant
CVE-2026-43904 HIGH 7.8 UPGRADE OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant
CVE-2026-43905 HIGH 7.8 UPGRADE OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant
CVE-2026-43906 HIGH 7.8 UPGRADE OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant

References

← Back to latest CVEs