How severe is CVE-2026-42478?

CVE-2026-42478 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-42478 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-42478?

CVE-2026-42478 primarily affects Opencascade Open Cascade Technology. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-42478?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-42478 have an EU (EUVD) identifier?

Yes. CVE-2026-42478 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26601.

When was CVE-2026-42478 published?

CVE-2026-42478 was published on 2026-05-01 and last updated on 2026-06-17.

CVE-2026-42478

CVE-2026-42478 is a high-severity vulnerability in Opencascade Open Cascade Technology with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (12th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-26601
Weakness: CWE-476
Affected product: Opencascade Open Cascade Technology
Published: 2026-05-01
Last modified: 2026-06-17

Description

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

Frequently asked questions

What is CVE-2026-42478?: 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 of a corrupt or unvalidated pointer during shape construction in libTKDEVRML.so.
How severe is CVE-2026-42478?: CVE-2026-42478 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-42478 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-42478?: CVE-2026-42478 primarily affects Opencascade Open Cascade Technology. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-42478?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-42478 have an EU (EUVD) identifier?: Yes. CVE-2026-42478 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26601.
When was CVE-2026-42478 published?: CVE-2026-42478 was published on 2026-05-01 and last updated on 2026-06-17.

References

https://gist.github.com/sgInnora/dfba083d04906283e9c92aea78e2d94a

Affected products (7)

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:*:*:*:*:*:*

More vulnerabilities in Opencascade Open Cascade Technology

CVE-2026-42477 — High (CVSS 7.1): A heap-based out-of-bounds read vulnerability in RWObj_Reader::read in the OBJ file parser in Open CASCADE Technology…
CVE-2026-42476 — High (CVSS 7.1): Two heap-based out-of-bounds read vulnerabilities in the STL ASCII file parser in Open CASCADE Technology (OCCT)…
CVE-2026-42481 — Medium (CVSS 5.5): Open CASCADE Technology (OCCT) V8_0_0_rc5 contains multiple vulnerabilities in its IGES and STEP file parsers that can…
CVE-2026-42480 — Medium (CVSS 5.5): A stack-based out-of-bounds read vulnerability in VrmlData_Scene::ReadLine in the VRML parser in Open CASCADE…
CVE-2026-42479 — Medium (CVSS 5.5): An out-of-bounds read vulnerability in VrmlData_IndexedLineSet::TShape in the VRML parser in Open CASCADE Technology…

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