CVE-2026-42479

Out‑of‑Bounds Read in Open CASCADE VRML Parser Causing Denial of Service

Published May 1, 2026 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
An out-of-bounds read vulnerability in VrmlData_IndexedLineSet::TShape in the VRML parser in Open CASCADE Technology (OCCT) V8_0_0_rc5 allows attackers to cause a denial of service via a crafted VRML file. The issue occurs because coordIndex values from parsed input are used as direct array indices without validation against the size of the coordinate array during geometry processing.

Analysis

AI-generated

Technical impact

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).

Affected Systems

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.

Risk and Exploitability

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.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Apply any available update or patch to the Open CASCADE Technology V8_0_0_rc5 release.
  • Validate VRML files before ingestion, ensuring coordIndex values stay within the bounds of the coordinate array, or reject files that violate this rule.
  • Run the VRML parser in a restricted or sandboxed environment so that a crash cannot compromise the host system.

Generated by OpenCVE AI on May 2, 2026 at 08:01 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Title Out‑of‑Bounds Read in Open CASCADE VRML Parser Causing Denial of Service
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

Type Values Removed Values Added
First Time appeared Opencascade
Opencascade open Cascade Technology
Weaknesses CWE-125
CPEs cpe:2.3:a:opencascade:open_cascade_technology:*:*:*:*:*:*:*:*
cpe:2.3:a:opencascade:open_cascade_technology:8.0.0:beta1:*:*:*:*:*:*
cpe:2.3:a:opencascade:open_cascade_technology:8.0.0:rc1:*:*:*:*:*:*
cpe:2.3:a:opencascade:open_cascade_technology:8.0.0:rc2:*:*:*:*:*:*
cpe:2.3:a:opencascade:open_cascade_technology:8.0.0:rc3:*:*:*:*:*:*
cpe:2.3:a:opencascade:open_cascade_technology:8.0.0:rc4:*:*:*:*:*:*
cpe:2.3:a:opencascade:open_cascade_technology:8.0.0:rc5:*:*:*:*:*:*
Vendors & Products Opencascade
Opencascade open Cascade Technology
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

Type Values Removed Values Added
Description An out-of-bounds read vulnerability in VrmlData_IndexedLineSet::TShape in the VRML parser in Open CASCADE Technology (OCCT) V8_0_0_rc5 allows attackers to cause a denial of service via a crafted VRML file. The issue occurs because coordIndex values from parsed input are used as direct array indices without validation against the size of the coordinate array during geometry processing.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
May 1, 2026, 6:29 PM
Reserved
Apr 27, 2026, 12:00 AM
Status
Modified
Published
May 1, 2026, 3:16 PM
Modified
Nov 8, 2026, 4:10 PM