CVE-2026-63635 in OpenImageIO
Summary
by MITRE • 09/18/2026
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 psd with an invalid color_mode bypasses normal validation when oiio:rawcolor or psd:rawdata is enabled. psdinput::setup() then uses the attacker-controlled value to index fixed color-mode tables, causing a global out-of-bounds read and potentially a bogus allocation, resulting in denial of service. The affected implementation is identified by src/psd.imageio/psdinput.cpp, PSDInput::validate_header(), PSDInput::setup(), oiio:RawColor, psd:RawData, color_mode, and mode_channel_count, 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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Analysis
by VulDB Data Team • 09/18/2026
OpenImageIO serves as a critical toolset within the visual effects and animation industries for reading, writing, and manipulating image files across various formats. A significant security vulnerability was identified in versions prior to 3.0.21.0, 3.1.16.0, and 3.2.0.3-beta1 concerning the handling of Photoshop Document (PSD) files. The flaw resides specifically within the PSD input module implementation found in src/psd.imageio/psdinput.cpp. This vulnerability allows an attacker to craft a malicious PSD file containing an invalid color_mode value that bypasses normal validation checks when specific flags, namely oiio:rawcolor or psd:rawdata, are enabled during processing.
The technical root cause of this issue lies in the interaction between header validation and subsequent setup procedures within the PSDInput class. When the aforementioned raw data options are active, the application fails to adequately sanitize or validate the color_mode field extracted from the file header before it is utilized by the PSDInput::setup() function. Consequently, the attacker-controlled value derived from the malicious input is used directly as an index into fixed internal tables related to color modes and channel counts. This lack of bounds checking leads to a global out-of-bounds read operation where memory outside the intended array boundaries is accessed based on the arbitrary index provided by the crafted file.
The operational impact of this vulnerability primarily manifests as a denial of service condition for applications relying on OpenImageIO for image processing workflows. The out-of-bounds read can result in undefined behavior, including potential crashes or segmentation faults due to accessing invalid memory addresses. Furthermore, the description notes that this flaw may lead to a bogus allocation, which could exacerbate stability issues and potentially introduce further risks if the corrupted data influences subsequent memory management operations. For professionals working with high-volume image processing pipelines, such instability can disrupt production schedules and compromise system reliability.
From a classification perspective, this vulnerability aligns with CWE-125, Out-of-bounds Read, as it involves reading beyond allocated buffer boundaries due to improper validation of input data indices. It also relates to CWE-20, Improper Input Validation, since the application failed to verify that the color_mode value fell within acceptable limits before using it in critical logic paths. In terms of attack vectors and techniques, this scenario is consistent with ATT&CK technique T1189, Drive-by Compromise or T1203, Exploitation for Client Execution if the vulnerability were leveraged to trigger further malicious actions through a compromised renderer, though currently documented impacts are limited to denial of service.
To mitigate this risk, organizations and developers must ensure that all instances of OpenImageIO in their production environments are upgraded to version 3.0.21.0 or later for the 3.0 branch, version 3.1.16.0 or later for the 3.1 branch, or version 3.2.0.3-beta1 and newer for the development track. These releases contain patches that enforce stricter validation of input parameters within the PSDInput::validate_header() function and ensure safe indexing practices in PSDInput::setup(). Additionally, implementing strict file type verification and sandboxing image processing tasks can provide defense-in-depth measures against similar vulnerabilities in other libraries or future updates.