What’s Vulnerable › Vulnerabilities

CVE-2025-64183: OpenEXR has use after free in PyObject_StealAttrString

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2025-11-10 · updated 2026-06-17
• Weakness: CWE-416

Description

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. In versions 3.2.0 through 3.2.4, 3.3.0 through 3.3.5, and 3.4.0 through 3.4.2, there is a use-after-free in PyObject_StealAttrString of pyOpenEXR_old.cpp. The legacy adapter defines PyObject_StealAttrString that calls PyObject_GetAttrString to obtain a new reference, immediately decrefs it, and returns the pointer. Callers then pass this dangling pointer to APIs like PyLong_AsLong/PyFloat_AsDouble, resulting in a use-after-free. This is invoked in multiple places (e.g., reading PixelType.v, Box2i, V2f, etc.) Versions 3.2.5, 3.3.6, and 3.4.3 fix the issue.

Affected products

• AcademySoftwareFoundation openexr: from 3.2.0 before 3.2.5; from 3.3.0 before 3.3.6; from 3.4.0 before 3.4.3 — fixed in 3.2.5, 3.3.6, 3.4.3

How to fix

Upgrade to a fixed version: AcademySoftwareFoundation openexr 3.2.5, 3.3.6, 3.4.3. Check the vendor advisory for mitigations.

References

• https://github.com/AcademySoftwareFoundation/openexr/blob/b3a19903db0672c63055023aa788e592b16ec3c5/src/wrappers/python/PyOpenEXR_old.cpp#L109-L115
• https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-57cw-j6vp-2p9m
• https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-57cw-j6vp-2p9m

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