Assimp CVE-2026-117608

Exploitation requires a victim application that uses Assimp's MD2 (Quake II model) importer to parse an attacker-supplied .md2 file; the trigger is attacker-controlled numFrames and numVertices header fields whose product overflows the 32-bit size calculation in MD2Importer::ValidateHeader() and wraps past the fileSize bounds check. No authentication is required (PR:N), but the attack is local/file-based (AV:L) and needs the file to be delivered to and processed by the host application (UI:P) - there is no standalone network-reachable service. Limiting factors: the target application must accept and import untrusted .md2 files, the impact is confined to a crash and limited adjacent-heap disclosure (no code execution or write), and systems updated past 6.0.5 are not affected.

This is a medium-severity (CVSS 4.0 base 6.9) memory-safety flaw in the Assimp MD2 importer, and the signals are internally consistent rather than conflicting. The 4.0 vector (AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H) describes an unauthenticated (PR:N) but local, file-parsing issue: the attacker does not supply credentials, yet the malicious .md2 must be delivered to and processed by an application that embeds Assimp, and passive user/application interaction is required (UI:P). The dominant impact is availability (VA:H, application crash) with only limited confidentiality exposure (VC:L, adjacent heap memory via out-of-bounds read); there is no integrity impact (VI:N), consistent with CWE-190 leading to a heap OOB read rather than write/code execution. No EPSS score is provided and the flaw is not on the CISA KEV list, so there is no evidence of active exploitation; the vulnerability was reported by VulnCheck and the vendor has shipped a patch. The vuln.today decision label is 'this_month' (not act_now/emergency), which matches a patchable DoS/info-leak in a widely embedded library rather than an urgent RCE. Net: a real but moderate-priority issue - prioritize patching in software that ingests untrusted 3D assets, but it is not a drop-everything emergency on the available signals. EPSS is absent, so probabilistic exploitation likelihood could not be weighed.

An attacker crafts a malicious Quake II .md2 model file whose numFrames and numVertices header fields are chosen so their 32-bit product wraps past the file-size bounds check in MD2Importer::ValidateHeader(). When a victim application that uses Assimp (e.g. a game engine, 3D asset pipeline, or model viewer) imports the file, the bypassed check lets the parser read beyond the allocated buffer, crashing the application or leaking adjacent heap memory. A public PoC reference exists (vendor issue report); it is not verified as working exploit code.