CVE-2026-32845 in cgltf
Summary
by MITRE • 03/23/2026
cgltf version 1.15 and prior contain an integer overflow vulnerability in the cgltf_validate() function when validating sparse accessors that allows attackers to trigger out-of-bounds reads by supplying crafted glTF/GLB input files with attacker-controlled size values. Attackers can exploit unchecked arithmetic operations in sparse accessor validation to cause heap buffer over-reads in cgltf_calc_index_bound(), resulting in denial of service crashes and potential memory disclosure.
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Analysis
by VulDB Data Team • 03/28/2026
The vulnerability identified as CVE-2026-32845 resides within the cgltf library version 1.15 and earlier, representing a critical integer overflow flaw that specifically impacts the cgltf_validate() function during the processing of sparse accessors in glTF/GLB files. This issue manifests when the library validates sparse accessors that contain attacker-controlled size values, creating a scenario where unchecked arithmetic operations can lead to catastrophic memory access violations. The vulnerability operates at the intersection of software security and graphics file parsing, where legitimate file validation processes become vectors for exploitation through malformed input data.
The technical flaw stems from improper bounds checking within the cgltf_calc_index_bound() function, which is invoked during sparse accessor validation. When processing sparse accessors, the library performs arithmetic operations on size values provided in the glTF/GLB input files without adequate overflow protection mechanisms. This allows attackers to craft malicious input files containing oversized size parameters that, when processed, result in integer overflow conditions. The overflow subsequently triggers heap buffer over-reads, where the application attempts to access memory locations beyond the allocated buffer boundaries, leading to unpredictable behavior and system instability.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially expose sensitive memory contents to attackers. When the integer overflow occurs during sparse accessor validation, the resulting heap buffer over-reads can cause application crashes while simultaneously providing opportunities for memory disclosure attacks. This dual nature of the vulnerability makes it particularly dangerous in environments where cgltf is used for processing untrusted glTF/GLB content, such as web browsers, 3D modeling applications, or game engines that rely on this library for asset loading. The vulnerability affects systems that process 3D graphics files, including but not limited to mobile applications, web-based 3D viewers, and desktop software that handles glTF format files.
Mitigation strategies for CVE-2026-32845 primarily focus on immediate library updates to versions that address the integer overflow condition in cgltf_validate() and cgltf_calc_index_bound() functions. Organizations should prioritize upgrading to cgltf version 1.16 or later, which includes proper bounds checking and overflow protection mechanisms for sparse accessor validation. Additionally, implementing input validation measures at the application level can provide defense-in-depth protection, including size parameter validation, memory access monitoring, and sandboxing techniques for glTF/GLB file processing. The vulnerability aligns with CWE-190, Integer Overflow or Wraparound, and can be mapped to ATT&CK technique T1203, Exploitation for Client Execution, when exploited in web browser contexts. Security practitioners should also consider implementing network-based intrusion detection systems that can identify and block suspicious glTF/GLB file patterns that may indicate exploitation attempts.