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Open Cascade TechnologyApplication · Opencascade

CVE-2026-42480

MEDIUM · 5.5 CVSS v3.1 Published 2026-05-01
Fix available
A fix is available. Upgrade to after 7.9.3 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A stack-based out-of-bounds read vulnerability in VrmlData_Scene::ReadLine 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 the quoted-string escape handler uses ptr[++anOffset] without proper bounds checking, which can read past the end of a fixed-size stack buffer.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A stack-based out-of-bounds read vulnerability exists in VrmlData_Scene::ReadLine within the VRML parser of Open CASCADE Technology V8_0_0_rc5. The quoted-string escape handler increments a pointer offset (ptr[++anOffset]) without validating buffer boundaries, allowing reads past the end of a fixed-size stack buffer when parsing crafted VRML files.

MitigationAvoid opening untrusted VRML files with affected OCCT versions until an official patch is available; implement bounds checking on the offset before accessing the buffer in the quoted-string escape handler.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Open Cascade TechnologyApplication
Affected:<= 7.9.3= 8.0.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Open CASCADE Technology version
    Check the installed OCCT library version by examining the shared library file (such as libTKVRML.so, TKVRML.dll, or similar), using commands like 'strings', 'file ver', or checking the product's 'About' dialog if using an application built on OCCT
    Affected if the version is 8.0.0 or falls at or below 7.9.3
  2. Confirm VRML parsing module is in use
    Inspect the application's loadable modules or linked libraries to verify that the VRML parser component (TKVRML) is loaded or linked into the process
    Affected if TKVRML module is loaded and active in the process memory space
  3. Check for active VRML file processing
    Review application logs, audit file access events, or monitor network/file inputs for .wrl or .vrml file operations being performed
    Affected if the application is actively reading or parsing VRML files from any source
  4. Identify source of VRML files
    Examine file import sources, user upload workflows, or network endpoints that feed VRML content into the VRML parser
    Affected if the VRML files being processed originate from untrusted or external sources without prior sanitization

A user is affected if their Open CASCADE Technology installation is version 8.0.0 or <= 7.9.3 AND the VRML parser module is actively processing VRML files, particularly those from untrusted sources.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 7.9.3
Interim mitigation

Avoid opening untrusted VRML files with affected OCCT versions until an official patch is available; implement bounds checking on the offset before accessing the buffer in the quoted-string escape handler.

Recommended fix Moderate confidence

OCCT 7.9.4 or OCCT 8.0.1 (or later stable release)

  1. 1. Identify all deployed instances of Open CASCADE Technology (OCCT) versions 7.9.3 or earlier, or version 8.0.0
  2. 2. Verify the specific OCCT version in use by checking the product version or library metadata
  3. 3. Download the fixed OCCT version (7.9.4 or 8.0.1 or later) from the official Open CASCADE distribution (dev.opencascade.org)
  4. 4. Replace the vulnerable OCCT libraries with the fixed version
  5. 5. Rebuild any applications that link against OCCT libraries to ensure they use the updated version
  6. 6. Re-test VRML file parsing functionality to confirm the fix works correctly
  7. 7. Re-scan or re-validate any existing VRML files that were processed during the vulnerable period if suspicion of compromise exists
Caveat Minor: Verify that any custom code relying on specific behaviors of VrmlData_Scene::ReadLine remains compatible, as bounds-checking changes may affect edge-case parsing behavior

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Open Cascade Technology Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing5.0 h
  • Review / QA3.0 h
17.0 hours of engineering $2,970
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-42480 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data