An out-of-bounds read vulnerability exists in the VRML parser of Open CASCADE Technology (OCCT) version V8_0_0_rc5. The flaw arises because coordinate indices are used directly as array indices when building line shapes, with no bounds checking. This permits an attacker to supply a malicious VRML file that, when parsed, causes the application to read beyond allocated memory and ultimately crash, resulting in a denial of service. The weakness corresponds to out‑of‑bounds read (CWE‑125).

The affected product is Open CASCADE Technology (OCCT) version V8_0_0_rc5. Systems that incorporate this release and process VRML files via the VrmlData_IndexedLineSet::TShape component are vulnerable. The flaw has not been identified in other versions of OCCT, and no specific vendor release notes are currently available.

Because the attack requires only a crafted VRML file, the attack surface is potentially high for any environment that accepts VRML input. The EPSS score is not available and the vulnerability is not listed in the CISA KEV catalog, so the exact exploitation likelihood is unknown. However, the vulnerability can be triggered by simply parsing a malicious file, and the absence of validation makes it relatively easy to write an exploit. In environments where the VRML parser runs with system privileges, the impact could be catastrophic. The CVSS score of 5.5 indicates a medium severity, reflecting a moderate risk.