CVE-2026-111128 in Assimp
Summary
by MITRE • 10/15/2026
Assimp through 6.0.5 contains a NULL pointer dereference vulnerability in the Ogre3D importer that allows attackers to crash applications via unvalidated bone indices in OgreStructs.cpp. Attackers can supply a crafted .mesh and .skeleton file referencing a missing bone, causing BoneById() to return null and crash the host process.
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Analysis
by VulDB Data Team • 10/15/2026
The Assimp library, specifically through version 6.0.5, contains a critical NULL pointer dereference vulnerability within its Ogre3D importer module. This flaw resides in the code responsible for parsing mesh and skeleton data structures defined by the Ogre3D engine format. The specific point of failure occurs when processing bone index references contained within OgreStructs.cpp. When Assimp processes these files, it attempts to resolve bone identifiers by calling a function named BoneById(). Under normal circumstances, this function returns a valid pointer to the requested bone object if the identifier exists in the loaded skeleton data. However, due to insufficient input validation, the library fails to verify whether the referenced bone index actually corresponds to an existing entry before proceeding with operations that assume the return value is non-null.
This technical flaw allows attackers to craft malicious .mesh and .skeleton files that reference a bone index which does not exist in the associated skeleton data structure. When such a crafted file is processed by Assimp, the BoneById() function returns NULL because it cannot locate the specified bone identifier within the available dataset. The application logic subsequently attempts to dereference this null pointer to access properties or methods of the non-existent bone object. This action triggers an immediate segmentation fault or access violation, causing the host process to crash abruptly. Since Assimp is widely used as a foundational component in many 3D graphics engines and game development tools for loading various asset formats, any application integrating this library becomes susceptible to denial-of-service attacks via file processing.
The operational impact of this vulnerability is primarily limited to availability, manifesting as a local or remote denial-of-service condition depending on how the vulnerable Assimp instance is integrated into an application. If an attacker can trick a user into opening a malicious 3D asset file within a compromised viewer or editor, they can cause the application to terminate unexpectedly. While this does not directly lead to arbitrary code execution in most standard configurations due to modern memory protection mechanisms like DEP and ASLR, it disrupts workflow integrity and can be used as part of a larger attack chain where stability is required for subsequent exploitation steps. The lack of bounds checking on bone indices represents a classic input validation failure that undermines the robustness of asset parsing routines.
From a classification perspective, this vulnerability aligns with CWE-476, which denotes NULL Pointer Dereference. This category encompasses errors resulting from dereferencing pointers without confirming they are non-null beforehand. In terms of offensive security frameworks, this behavior is consistent with techniques found in the MITRE ATT&CK catalog under Denial of Service (T1499), specifically where an attacker disrupts service availability by causing application crashes through malformed inputs. The vulnerability highlights the importance of rigorous validation when parsing external binary or text-based asset formats that may be sourced from untrusted origins.
To mitigate this risk, developers integrating Assimp must ensure they are using a patched version of the library released after 6.0.5 where this specific check has been implemented. For applications relying on older versions, implementing wrapper logic to validate bone indices before passing them to Assimp functions can provide an additional layer of defense. Furthermore, running asset processing tasks in isolated sandboxed environments or with restricted privileges limits the potential impact if a crash occurs. Security teams should also audit their use of third-party 3D parsing libraries for similar patterns of unchecked pointer returns and implement comprehensive error handling that gracefully manages malformed input rather than allowing unhandled exceptions to terminate processes. Regular updates to dependencies are essential as open-source projects frequently patch such stability issues in subsequent releases.