CVE-2026-62986

OpenEXR: PyOpenEXR deep prefixed RGB stale lane disclosure

Published Aug 25, 2026 CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Description
OpenEXR is the reference implementation and specification for the EXR image file format, widely used in the motion picture industry. In versions 3.3.0 through 3.3.12 and 3.4.0 through 3.4.13, the PyOpenEXR Python bindings return stale heap data when reading a crafted deep scanline EXR that uses layer-prefixed RGB channels. With the default channel coalescing (separate_channels=False), the wrapper groups channels such as left.R, left.G, and left.B into a single RGB sample array, but the lane-offset calculation in PyPart::setDeepSliceData() only recognizes the exact unprefixed names G, B, and A. As a result, prefixed channels like left.G and left.B are decoded into lane 0 while lanes 1 and 2 are left uninitialized and returned to Python. A Python application that reads untrusted deep EXR files through the default OpenEXR.File API and then logs, serializes, previews, or otherwise processes the resulting NumPy sample arrays may expose uninitialized same-process heap contents, in addition to receiving incorrect green and blue channel data. This issue is fixed in versions 3.3.13 and 3.4.14.

Remediation

No solution or workaround provided in the CVE record

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History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description OpenEXR is the reference implementation and specification for the EXR image file format, widely used in the motion picture industry. In versions 3.3.0 through 3.3.12 and 3.4.0 through 3.4.13, the PyOpenEXR Python bindings return stale heap data when reading a crafted deep scanline EXR that uses layer-prefixed RGB channels. With the default channel coalescing (separate_channels=False), the wrapper groups channels such as left.R, left.G, and left.B into a single RGB sample array, but the lane-offset calculation in PyPart::setDeepSliceData() only recognizes the exact unprefixed names G, B, and A. As a result, prefixed channels like left.G and left.B are decoded into lane 0 while lanes 1 and 2 are left uninitialized and returned to Python. A Python application that reads untrusted deep EXR files through the default OpenEXR.File API and then logs, serializes, previews, or otherwise processes the resulting NumPy sample arrays may expose uninitialized same-process heap contents, in addition to receiving incorrect green and blue channel data. This issue is fixed in versions 3.3.13 and 3.4.14.
Title OpenEXR: PyOpenEXR deep prefixed RGB stale lane disclosure
Weaknesses CWE-200
CWE-457
CWE-908
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N'}

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Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 25, 2026, 7:20 PM
Reserved
Jul 14, 2026, 10:48 PM
Status
Deferred
Published
Aug 25, 2026, 7:16 PM
Modified
Sep 9, 2026, 9:07 PM