CVE-2026-42476: Two heap-based out-of-bounds read vulnerabilities in the STL ASCII file parser in Open CASCADE Technology (OCC

Q: How do I fix CVE-2026-42476?

open cascade technology: upgrade to newer than 7.9.3. Exact commands for each OS are on this page.

Q: Is CVE-2026-42476 being exploited?

CVE-2026-42476 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-42476 affect?

CVE-2026-42476 affects open cascade technology. Severity is high (CVSS 7.1). Two heap-based out-of-bounds read vulnerabilities in the STL ASCII file parser in Open CASCADE Technology (OCCT) V8_0_0_rc5 exist in RWStl_Reader::ReadAscii because buffers returned by Standard_ReadLineBuffer::ReadLine() are not properly le

Routine

HIGH 7.1UPGRADE

CVE-2026-42476 is a high-severity flaw (CVSS 7.1) affecting open cascade technology. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Two heap-based out-of-bounds read vulnerabilities in the STL ASCII file parser in Open CASCADE Technology (OCCT) V8_0_0_rc5 exist in RWStl_Reader::ReadAscii because buffers returned by Standard_ReadLineBuffer::ReadLine() are not properly length-validated before strncasecmp or direct byte access. User-assisted attackers can trigger these issues by persuading a victim to open a crafted STL file with extremely short lines, resulting in a denial of s

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.1 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.1% (top 99%)
CISA exploited list	No
Weakness	CWE-125
Published	2026-05-01
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: opencascade

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-01 15:16 UTCPublished CVE record published
2026-06-17 10:47 UTCUpdated Record last modified

opencascade open cascade technology UPGRADE

Affected: <= 7.9.3 · 8.0.0 beta1 · 8.0.0 rc1 · 8.0.0 rc2 · 8.0.0 rc3 · 8.0.0 rc4 · 8.0.0 rc5

Fixed in: newer than 7.9.3

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy open-cascade-technology || rpm -q open-cascade-technology || open-cascade-technology --version

2. UPGRADE to newer than 7.9.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade open-cascade-technology

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade open-cascade-technology

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-42476?

open cascade technology: upgrade to newer than 7.9.3. Exact commands for each OS are on this page.

Is CVE-2026-42476 being exploited?

CVE-2026-42476 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-42476 affect?

CVE-2026-42476 affects open cascade technology. Severity is high (CVSS 7.1). Two heap-based out-of-bounds read vulnerabilities in the STL ASCII file parser in Open CASCADE Technology (OCCT) V8_0_0_rc5 exist in RWStl_Reader::ReadAscii because buffers returned by Standard_ReadLineBuffer::ReadLine() are not properly le

How urgent is CVE-2026-42476?

Priority 25/100. High severity

Related CVEs

CVE-2026-42481 MEDIUM 5.5 UPGRADE Open CASCADE Technology (OCCT) V8_0_0_rc5 contains multiple vulnerabilities in its IGES and STEP file parsers
CVE-2026-42480 MEDIUM 5.5 UPGRADE A stack-based out-of-bounds read vulnerability in VrmlData_Scene::ReadLine in the VRML parser in Open CASCADE
CVE-2026-42479 MEDIUM 5.5 UPGRADE An out-of-bounds read vulnerability in VrmlData_IndexedLineSet::TShape in the VRML parser in Open CASCADE Tech
CVE-2026-42478 HIGH 7.5 UPGRADE An issue was discovered in VrmlData_IndexedFaceSet::TShape in the VRML V2.0 parser in Open CASCADE Technology
CVE-2026-42477 HIGH 7.1 UPGRADE A heap-based out-of-bounds read vulnerability in RWObj_Reader::read in the OBJ file parser in Open CASCADE Tec

References

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