# CVE-2025-5865: RT-Thread Parameter lwp_syscall.c sys_select memory corruption

> Attackers can trigger memory corruption in RT-Thread via the sys_select timeout parameter, potentially leading to code execution or privilege escalation.

- **Severity:** High 8.6 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X`)
- **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:** 9 Jun 2025
- **Updated:** 9 Jun 2025
- **Also known as:** GHSA-4xh2-4xwh-6pgr

## What is CVE-2025-5865?

CVE-2025-5865 is a high-severity memory corruption vulnerability in RT-Thread, published on 9 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability was found in RT-Thread 5.1.0. It has been rated as critical. Affected by this issue is the function sys_select of the file rt-thread/components/lwp/lwp_syscall.c of the component Parameter Handler. The manipulation of the argument timeout leads to memory corruption. The vendor explains, that "[t]he timeout parameter should be checked to check if it can be accessed correctly in kernel mode and used temporarily in kernel memory."

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2025-5865?

It affects 1 product.


Products: Rt-Thread Rt-Thread.

## How do I fix CVE-2025-5865?

No fix has been published for CVE-2025-5865 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-5865 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-5865 exists.

## Other vulnerabilities in RT-Thread

- [CVE-2024-25393](https://insights.sbomify.com/CVE-2024-25393/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-25395](https://insights.sbomify.com/CVE-2024-25395/): Memory corruption in n/a (high 8.8)
- [CVE-2025-5866](https://insights.sbomify.com/CVE-2025-5866/): RT-Thread lwp_syscall.c sys_sigprocmask array index (high 8.6)
- [CVE-2025-5867](https://insights.sbomify.com/CVE-2025-5867/): RT-Thread lwp_syscall.c csys_sendto null pointer dereference (high 8.6)
- [CVE-2025-5868](https://insights.sbomify.com/CVE-2025-5868/): RT-Thread lwp_syscall.c sys_thread_sigprocmask array index (high 8.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-5865 and fix it if it is affected.

What it is: CVE-2025-5865 is a high-severity memory corruption vulnerability in RT-Thread, published on 9 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-5865 exists.

Affected product: RT-Thread. 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-2025-5865/ (Markdown: https://insights.sbomify.com/CVE-2025-5865/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-5865
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-5865
- OSV: https://osv.dev/vulnerability/CVE-2025-5865

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From sbomify Insights: https://insights.sbomify.com/CVE-2025-5865/
Summaries are generated and may contain mistakes; the official description above is the record.