Cyber Resilience

CVE-2026-42478

Memory Safety in Opencascade Open Cascade Technology ≤ 7.9.3

Published
01 May 2026
Modified
01 May 2026
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0022 13th percentile
Risk Priority 56 floored blend · peak EPSS

Summary

CVE-2026-42478 is a high-severity NULL Pointer Dereference (CWE-476) vulnerability in Opencascade Open Cascade Technology. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 13th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-42478 affects the VRML V2.0 parser in Open CASCADE Technology (OCCT) version V8_0_0_rc5, specifically in the VrmlData_IndexedFaceSet::TShape component within the libTKDEVRML.so library. The vulnerability arises from malformed VRML input that triggers a dereference of a corrupt or unvalidated pointer during shape construction, leading to a denial of service. It is linked to CWE-476 (NULL Pointer Dereference) and CWE-125 (Out-of-bounds Read), with a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), indicating high severity due to availability impact.

Attackers can exploit this vulnerability remotely over the network with low attack complexity, no required privileges, and no user interaction. By supplying a crafted VRML file to an application that processes VRML content using the affected OCCT parser, an attacker can cause a crash or resource exhaustion, resulting in denial of service on the targeted system.

Mitigation details are available in the referenced advisory at https://gist.github.com/sgInnora/dfba083d04906283e9c92aea78e2d94a.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

An issue was discovered in VrmlData_IndexedFaceSet::TShape in the VRML V2.0 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 malformed VRML input can trigger dereference…

more

of a corrupt or unvalidated pointer during shape construction in libTKDEVRML.so.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-29835Shared CWE-125, CWE-476
CVE-2024-47602Shared CWE-125, CWE-476
CVE-2026-56017Shared CWE-125, CWE-476
CVE-2026-32738Shared CWE-125, CWE-476
CVE-2026-41069Shared CWE-125, CWE-476
CVE-2023-51391Shared CWE-125, CWE-476
CVE-2026-30986Shared CWE-125, CWE-476
CVE-2024-47542Shared CWE-125, CWE-476
CVE-2024-23808Shared CWE-125, CWE-476
CVE-2026-39956Shared CWE-125, CWE-476

Affected Assets

opencascade
open cascade technology
8.0.0 · ≤ 7.9.3

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (including static analysis) directly finds null-dereference bugs before deployment.

Documented development standards and tools can enforce null-safety rules and safe pointer usage.

Engineering principles can mandate defensive coding such as explicit null checks before dereference.

Process isolation confines the effects of an out-of-bounds read to the compromised process.

Input validation rejects malformed indices or lengths that would otherwise cause reads outside buffer bounds.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices (static analysis, code review, safe coding standards) directly prevent NULL dereference bugs during development.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing out-of-bounds read flaws.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect NULL dereference defects before release.

A.8.15 Logging partial match
finds

Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.

prevents

Secure SDLC mandates defensive coding practices that can prevent NULL dereferences.

prevents

Application security requirements can specify input validation and pointer-safety rules.

prevents

Secure architecture principles encourage defensive design that avoids unsafe pointer use.

prevents

Secure coding standards directly require NULL-pointer checks and safe dereference patterns.

References