CVE-2026-129479 in Assimp
Summary
by MITRE • 11/15/2026
Assimp through 6.0.6 contains an integer overflow vulnerability in OgreBinarySerializer::ReadSubMesh that allows attackers to crash applications by supplying crafted Ogre binary .mesh files. Attackers can set a large index count so the 32-bit buffer size wraps, causing a segmentation fault in aiMesh::~aiMesh() during scene teardown.
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Analysis
by VulDB Data Team • 11/15/2026
The Assimp library, specifically through version 6.0.6, contains a critical integer overflow vulnerability within the OgreBinarySerializer::ReadSubMesh function that poses significant risks to application stability and availability. This flaw arises from improper handling of index counts when parsing Ogre binary mesh files, allowing attackers to craft malicious .mesh files with excessively large index values. When such a file is processed, the library attempts to allocate memory for an array based on this unvalidated count without performing adequate bounds checking or overflow detection prior to allocation.
The technical core of the vulnerability lies in the arithmetic operation used to calculate buffer size. The code multiplies the number of indices by the size of each index element, resulting in a 32-bit integer calculation that can wrap around when the product exceeds the maximum value representable by a signed or unsigned 32-bit integer. This wrapping effect causes the allocated memory buffer to be significantly smaller than required for storing the actual data contained within the file. Consequently, subsequent operations that write index data into this undersized buffer result in heap-based buffer overflows, corrupting adjacent memory structures and leading to undefined behavior during execution.
The operational impact of this vulnerability is primarily focused on denial of service through application crashes rather than remote code execution or privilege escalation. When the corrupted state manifests during scene teardown, specifically within the destructor aiMesh::~aiMesh(), the program encounters a segmentation fault due to invalid memory access patterns resulting from the prior corruption. This crash prevents legitimate users from accessing 3D content processed by Assimp and can disrupt services relying on stable rendering pipelines or asset loading mechanisms that depend on this library for parsing Ogre format files.
From an industry standard perspective, this vulnerability aligns with CWE-190 Integer Overflow or Wraparound, as the root cause is the failure to handle arithmetic operations correctly when values approach system limits. It also relates to CWE-787 Out-of-bounds Write, since the undersized allocation leads to writes beyond allocated memory boundaries. In terms of attack vectors and tactics, this flaw can be exploited via ATT&CK technique T1496 Resource Hijacking or more specifically within the context of application crashes under T1529 System Shutdown/Reboot if used in automated systems where availability is critical. However, it primarily falls under exploitation for denial-of-service impacts rather than data exfiltration or control takeover.
Mitigation strategies should focus on immediate patching to Assimp version 6.0.7 or later where this issue has been addressed by developers implementing proper validation checks before memory allocation. Input sanitization techniques must be applied at the parser level to ensure that index counts do not exceed reasonable thresholds defined by the Ogre binary format specification. Additionally, employing static analysis tools capable of detecting integer overflow patterns and dynamic testing with fuzzing frameworks targeting mesh file parsers can help identify similar vulnerabilities in related code paths. Defense-in-depth measures such as memory protection mechanisms like ASLR and DEP provide additional layers against exploitation but do not replace the need for fixing the underlying logic error within the serializer component itself.