Assimp CVE-2026-10233

Local access with low operating-system privileges is required (CVSS AV:L/PR:L). The target application must invoke Assimp's Half-Life 1 MDL Loader to parse a crafted MDL file provided or placed by the attacker - the vulnerable code path (HL1MDLLoader::read_sequence_infos) is only triggered when processing HL1 MDL format files specifically, not other Assimp-supported formats. No user interaction is required beyond the application loading the file (UI:N). Exploitation is limited to memory disclosure (C:L); no integrity or availability impact has been identified, and scope is unchanged (S:U), meaning the attacker cannot leverage this bug alone to escape the application's privilege boundary. Remote exploitation is not possible per the local attack vector.

The base CVSS 3.1 score of 3.3 (Low) accurately reflects constrained real-world risk. The vector AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N requires local access with low privileges - ruling out remote or unauthenticated attack scenarios entirely. Impact is limited to partial memory disclosure with no write or denial-of-service primitive evident. The temporal modifier E:P (Proof-of-Concept) elevates practical concern marginally since exploit code is publicly available (POC zip hosted on GitHub), lowering the skill barrier for local attackers. However, the Remediation Level is RL:X (not defined) and Confidence is RC:R (reasonable), indicating some uncertainty remains in the full vulnerability profile. No EPSS score was provided in source data, so exploitation probability cannot be quantified. Absence from CISA KEV and the 'tagged as bug' project response suggest this has not been weaponized at scale. For most deployments the realistic priority is low - this is a local-only information disclosure with no lateral movement or privilege escalation primitive confirmed. Applications that process untrusted HL1 MDL files in multi-tenant or sandboxed environments should treat this with higher urgency.

A local attacker with standard user privileges places a crafted Half-Life 1 MDL file - constructed using the publicly available POC (https://github.com/user-attachments/files/27228962/poc.zip) - into a location processed by a target application using Assimp ≤ 6.0.4, such as a 3D editor, game asset pipeline, or conversion tool. When the application loads the file, read_sequence_infos reads beyond the intended buffer boundary for the aiString argument, potentially exposing adjacent heap or stack memory contents to the attacker. The leaked data could include pointers, keys, or other in-memory values depending on runtime memory layout.