CVE-2026-10199: Assimp Use-After-Free Vulnerability

CVE-2026-10199 Overview

CVE-2026-10199 is a null pointer dereference vulnerability in the Open Asset Import Library (Assimp) through version 6.0.4. The flaw resides in the glTF2::LazyDict function within the glTF2Asset.h header file. Manipulation of the operator[] argument triggers the dereference, causing the consuming application to crash. The issue is classified under [CWE-404] (Improper Resource Shutdown or Release) and requires local access with low privileges. A public proof-of-concept has been disclosed, and the maintainers have committed a fix referenced by patch hash d24b85319bd70c65883a2b96613e07e23fb95981.

Critical Impact
Local attackers can trigger a denial-of-service condition in applications that load attacker-controlled glTF2 assets through Assimp.

Affected Products

Assimp (Open Asset Import Library) versions up to and including 6.0.4
Applications and game engines bundling vulnerable Assimp builds
3D asset processing pipelines that parse glTF2 content using Assimp

Discovery Timeline

2026-05-31 - CVE-2026-10199 published to the National Vulnerability Database
2026-06-01 - Last updated in the NVD database

Technical Details for CVE-2026-10199

Vulnerability Analysis

The defect is a null pointer dereference reachable through the glTF2::LazyDict container defined in glTF2Asset.h. When the application invokes operator[] with a crafted index or key against an uninitialized internal pointer, the code path dereferences a null reference instead of validating the dictionary state. The consuming process terminates immediately with a segmentation fault.

Assimp is widely embedded in 3D rendering tools, game engines, and content creation pipelines. Any workflow that imports untrusted glTF2 files through a vulnerable Assimp build is exposed. Exploitation is limited to denial of service, with no path to code execution or information disclosure indicated in the available data.

A public proof-of-concept archive has been published alongside the disclosure on GitHub, lowering the barrier for triggering the crash against vulnerable consumers.

Root Cause

The LazyDict template lazily resolves backing storage when an element is requested. The vulnerable revision performs no null guard before dereferencing the internal pointer inside operator[]. Inputs that bypass deferred initialization expose the unchecked pointer, producing the fault. The remediation in commit d24b85319bd70c65883a2b96613e07e23fb95981 adds the missing validation.

Attack Vector

The attack vector is local. An attacker supplies a malformed glTF2 asset to a user or service that processes the file with a vulnerable Assimp build. Successful exploitation requires low privileges and no user interaction beyond the asset load. The result is a crash of the host process. See the GitHub Issue #6611 and GitHub PoC ZIP File for technical reproduction details.

Detection Methods for CVE-2026-10199

Indicators of Compromise

Unexpected segmentation faults or access violations in processes linked against libassimp while parsing glTF2 (.gltf, .glb) assets
Crash dumps showing fault addresses near zero with stack frames inside glTF2::LazyDict::operator[]
Malformed glTF2 files arriving from untrusted sources immediately preceding application termination

Detection Strategies

Inventory binaries that statically or dynamically link Assimp versions at or below 6.0.4 across build pipelines and shipped products
Enable core dump collection on workstations and render farms that ingest external 3D assets to capture LazyDict-related faults
Hash-match the patched commit d24b85319bd70c65883a2b96613e07e23fb95981 against vendored Assimp source trees to confirm patch status

Monitoring Recommendations

Alert on repeated process crashes in 3D content tooling, especially when correlated with newly received glTF2 files
Track file ingestion paths that accept user-submitted models and route them through fuzzing or sandboxed parsers before production use
Review EDR telemetry for abnormal termination of editor, viewer, or backend services that embed Assimp

How to Mitigate CVE-2026-10199

Immediate Actions Required

Update Assimp to a build that includes commit d24b85319bd70c65883a2b96613e07e23fb95981 or a release published after that fix
Rebuild and redistribute any downstream applications that statically link Assimp once the patched source is integrated
Restrict glTF2 imports to trusted sources until patched binaries are deployed across affected systems

Patch Information

The maintainers merged the fix through GitHub Pull Request #6646, referenced as patch GitHub Commit d24b853. Vendors shipping Assimp should pull the latest upstream from the GitHub Assimp Repository and reissue affected packages. Additional metadata is available at VulDB CVE-2026-10199.

Workarounds

Disable or remove the glTF2 importer in Assimp configuration when patching is not immediately feasible
Validate and sanitize incoming 3D assets in an isolated sandbox or container before passing them to production tooling
Run asset-processing services under least-privilege accounts so that a crash cannot cascade into broader service disruption

bash

# Build Assimp from patched source
git clone https://github.com/assimp/assimp.git
cd assimp
git checkout d24b85319bd70c65883a2b96613e07e23fb95981
cmake -S . -B build -DASSIMP_BUILD_TESTS=OFF
cmake --build build --config Release