# CVE-2026-42477: Memory corruption in n/a

> A heap-based out-of-bounds read in the OCCT OBJ parser allows attackers to cause denial of service or leak sensitive information via crafted files.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 May 2026
- **Updated:** 10 May 2026
- **Also known as:** DEBIAN-CVE-2026-42477, GHSA-3vcm-9wgv-947g, UBUNTU-CVE-2026-42477

## What is CVE-2026-42477?

CVE-2026-42477 is a medium-severity memory corruption vulnerability in n/a, published on 1 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A heap-based out-of-bounds read vulnerability in RWObj_Reader::read in the OBJ file parser in Open CASCADE Technology (OCCT) V8_0_0_rc5 allows user-assisted attackers to cause a denial of service or obtain sensitive information by persuading a victim to open a crafted OBJ file. The issue occurs because Standard_ReadLineBuffer::ReadLine() can return a 1-byte buffer for a minimal OBJ line, and RWObj_Reader::read() calls pushIndices(aLine + 2) without validating the buffer length.

Weakness: CWE-125 (Out-of-bounds Read), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-42477?

It affects 1 product.


Products: Opencascade Open Cascade Technology.

## How do I fix CVE-2026-42477?

No fix has been published for CVE-2026-42477 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-42477 being exploited?

There is no known exploitation of CVE-2026-42477 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2026-42476](https://insights.sbomify.com/CVE-2026-42476/): Memory corruption in n/a (medium 5.5)
- [CVE-2026-42478](https://insights.sbomify.com/CVE-2026-42478/): Null dereference in n/a (medium 5.5)
- [CVE-2026-42479](https://insights.sbomify.com/CVE-2026-42479/): Denial of service in n/a (medium 5.5)
- [CVE-2026-42480](https://insights.sbomify.com/CVE-2026-42480/): Denial of service in n/a (medium 5.5)
- [CVE-2026-42481](https://insights.sbomify.com/CVE-2026-42481/): Memory corruption in n/a (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42477 and fix it if it is affected.

What it is: CVE-2026-42477 is a medium-severity memory corruption vulnerability in n/a, published on 1 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-42477 in the wild and no public exploit code.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-42477/ (Markdown: https://insights.sbomify.com/CVE-2026-42477/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42477
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42477
- OSV: https://osv.dev/vulnerability/CVE-2026-42477

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-42477/
Summaries are generated and may contain mistakes; the official description above is the record.