CVE-2026-65969 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 truncated tga can leave a pending gif frame that is processed during output close. gifsplitpalette() computes numpixels multiplied by the palette partition width in signed 32-bit arithmetic; a large image overflows that intermediate, corrupts subpixelsa, and drives an out-of-bounds read while building the gif palette, resulting in a process crash and denial of service. The affected implementation is identified by src/gif.imageio/gif.h, GifSplitPalette(), numPixels, subPixelsA, GIFOutput, and truncated TGA input, 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 involving the handling of Truncated Targa (TGA) images during GIF output operations. The flaw originates from a logic error within the gifsplitpalette function, which is responsible for managing palette partitions when converting or processing image data into GIF format. This specific implementation detail highlights how internal state management and arithmetic operations can lead to severe runtime failures if input validation is insufficient.
The technical root cause of this vulnerability lies in signed 32-bit integer overflow during the calculation of pixel counts. Specifically, the gifsplitpalette function computes a value by multiplying numPixels by the palette partition width using signed 32-bit arithmetic. When processing large images or specific malformed inputs such as truncated TGA files, this multiplication can exceed the maximum positive value representable by a signed 32-bit integer. This overflow results in an incorrect negative or unexpectedly small intermediate result for subpixelsa. Consequently, subsequent logic that relies on these calculated values proceeds with corrupted data structures rather than detecting the arithmetic failure.
This corruption directly leads to an out-of-bounds read condition while building the GIF palette. Because the internal state variables are derived from invalid calculations, memory access patterns deviate from expected bounds. The application attempts to read pixel or palette data at addresses outside the allocated buffer boundaries. This unauthorized memory access triggers a process crash, effectively resulting in a denial of service for any user or automated pipeline relying on OpenImageIO for image processing tasks. In high-throughput environments such as rendering farms or CI/CD pipelines for VFX assets, this instability can cause significant workflow disruptions and data loss if not properly handled by wrapper scripts or monitoring systems.
From a classification perspective, this vulnerability aligns with CWE-190 Integer Overflow or Wraparound, which describes the flaw where arithmetic operations exceed the capacity of the variable type used to store them. Furthermore, it relates to CWE-787 Out-of-bounds Read, as the corrupted state leads to accessing memory beyond its intended limits. In terms of attack vectors and tactical mapping under MITRE ATT&CK, this issue represents a Denial of Service (T1499) capability where an attacker could potentially craft malicious TGA files to crash processing services. It also touches upon Improper Input Validation (CWE-20), as the software fails to adequately validate or sanitize input data before performing critical arithmetic operations that determine memory layout and access patterns.
The operational impact is primarily a stability issue rather than a direct code execution vector, although out-of-bounds reads can sometimes be leveraged for information disclosure depending on the surrounding context and compiler optimizations. However, in this specific case, the primary consequence is process termination due to segmentation faults or similar memory protection violations triggered by the invalid read operation. Mitigation strategies involve upgrading OpenImageIO to version 3.0.21.0, 3.1.16.0, or later beta versions where these arithmetic checks and bounds validations have been corrected. For environments unable to upgrade immediately, implementing strict input validation on TGA files before they are passed to the library can help prevent triggering this specific code path. Additionally, deploying runtime application self-protection tools that monitor for abnormal memory access patterns may provide an additional layer of defense against exploitation attempts targeting similar integer overflow vulnerabilities in image processing libraries.