CVE-2026-10199: Assimp Null Pointer Dereference in glTF2 Parsing

Technical summary

The vulnerability exists in the glTF2::LazyDict class within glTF2Asset.h. The issue stems from improper bounds checking in the operator[] function, which can be manipulated through carefully constructed glTF2 file arguments to dereference a null pointer. The attack vector is local, requires low privileges, and does not require user interaction. Both CWE-404 (Improper Resource Validation) and CWE-476 (Null Pointer Dereference) apply, indicating inadequate input validation leading to unsafe memory access.

Business impact

Organizations using Assimp in local processing pipelines—such as 3D asset conversion tools, game development workflows, or computer-aided design integrations—face denial-of-service risk. An attacker with system access (or able to place a malicious asset file on the system) can crash Assimp-dependent applications, disrupting asset pipelines or engineering workflows. The impact is limited to availability; no data exfiltration or privilege escalation is possible.

Affected systems

Assimp versions up to and including 6.0.4 are vulnerable. Any application embedding or calling Assimp for glTF2 file parsing is at risk. This includes game engines, 3D modeling tools, CAD software, and asset pipeline servers that accept user-provided or untrusted glTF2 files. Verify your specific Assimp version and update accordingly.

Exploitability

Exploitation requires local access and low privileges, but no authentication bypass or complex manipulation is needed. The public disclosure means attack code and reproduction techniques are accessible. However, real-world impact depends on whether the application processes untrusted glTF2 files or runs in an environment where local attackers are present. Environments that process only trusted, internally-generated assets face lower risk.

Remediation

Upgrade Assimp to a version containing the patch commit d24b85319bd70c65883a2b96613e07e23fb95981 or later. Verify the exact patch release version against the official Assimp repository and security advisories. As an interim measure, restrict file processing to trusted sources and disable glTF2 parsing if not required. Validate glTF2 file integrity before processing.

Patch guidance

Apply the patch corresponding to commit d24b85319bd70c65883a2b96613e07e23fb95981. Consult the Assimp GitHub repository and official security advisories for the specific version number and release date. Update all dependent applications and rebuild if Assimp is statically linked. Test patched versions in a staging environment before production deployment, particularly for critical asset pipeline infrastructure.

Detection guidance

Monitor for crashes or exceptions in Assimp-dependent applications when processing glTF2 files. Log and alert on null pointer exceptions in glTF2Asset.h. Implement file validation before passing glTF2 assets to Assimp (e.g., schema validation, file integrity checks). In development environments, enable address sanitizers (ASan) or memory debugging tools to catch null pointer dereferences during testing. Restrict file upload permissions to prevent injection of malicious assets.

Why prioritize this

Despite a low CVSS score of 3.3, prioritize this based on your asset pipeline architecture. If Assimp is embedded in critical production tools or processes untrusted external files, elevation to medium priority is justified. Organizations with sandboxed, offline asset processing or internal-only file sources can defer patching. The public disclosure means active exploitation risk is elevated relative to the base score alone.

Risk score, explained

The CVSS 3.1 score of 3.3 (LOW) reflects limited attack scope: local access, low privileges, no user interaction, and impact limited to availability (denial of service). The attack vector is not network-exploitable, reducing severity. However, the score does not account for how critical Assimp is to your specific workflows. Customize your internal risk rating based on whether you process untrusted files and the business cost of pipeline disruption.

Frequently asked questions