# CVE-2025-48990: NeKernel has Heap Overflow in `rt_copy_memory`

> A 1-byte heap overflow in NeKernel's rt_copy_memory function allows attackers to potentially execute code or crash the system.

- **Severity:** High 8.6 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Jun 2025
- **Updated:** 2 Jun 2025
- **Also known as:** GHSA-jvvh-fp57-2p32

## What is CVE-2025-48990?

CVE-2025-48990 is a high-severity memory corruption vulnerability in nekernel-org nekernel, published on 2 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

NeKernal is a free and open-source operating system stack. Version 0.0.2 has a 1-byte heap overflow in `rt_copy_memory`, which unconditionally wrote a null terminator at `dst[len]`. When `len` equals the size of the destination buffer (256 bytes), that extra `'\0'` write overruns the buffer by one byte. To avoid breaking existing callers or changing the public API, the patch in commit fb7b7f658327f659c6a6da1af151cb389c2ca4ee takes a minimal approach: it simply removes the overflow-causing line without adding bounds checks or altering the function signature.

Weakness: CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2025-48990?


## How do I fix CVE-2025-48990?

No fix has been published for CVE-2025-48990 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-48990 being exploited?

There is no known exploitation of CVE-2025-48990 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-48990 and fix it if it is affected.

What it is: CVE-2025-48990 is a high-severity memory corruption vulnerability in nekernel-org nekernel, published on 2 Jun 2025. 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-2025-48990 in the wild and no public exploit code.

Affected product: nekernel-org nekernel. 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-2025-48990/ (Markdown: https://insights.sbomify.com/CVE-2025-48990/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-48990
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-48990
- OSV: https://osv.dev/vulnerability/CVE-2025-48990

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From sbomify Insights: https://insights.sbomify.com/CVE-2025-48990/
Summaries are generated and may contain mistakes; the official description above is the record.