# CVE-2025-9389: vim memmove-vec-unaligned-erms.S __memmove_avx_unaligned_erms memory corruption

> Local attackers can exploit memory corruption in Vim's assembly code to execute arbitrary code or escalate privileges.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P`)
- **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:** Yes
- **Published:** 24 Aug 2025
- **Updated:** 25 Aug 2025
- **Also known as:** BELL-CVE-2025-9389, GHSA-p222-mxxm-v36m

## What is CVE-2025-9389?

CVE-2025-9389 is a medium-severity memory corruption vulnerability in Vim Vim, published on 24 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability was identified in vim 9.1.0000. Affected is the function __memmove_avx_unaligned_erms of the file memmove-vec-unaligned-erms.S. The manipulation leads to memory corruption. The attack needs to be performed locally. The exploit is publicly available and might be used. Some users are not able to reproduce this. One of the users mentions that this appears not to be working, "when coloring is turned on".

Weakness: CWE-787 (Out-of-bounds Write), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2025-9389?

It affects 1 product.


Products: Vim Vim.

## How do I fix CVE-2025-9389?

Apply the vendor's patch.

## Is CVE-2025-9389 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-9389 exists.

## Other vulnerabilities in Vim Vim

- [CVE-2020-20703](https://insights.sbomify.com/CVE-2020-20703/): Memory corruption in n/a (critical 9.8)
- [CVE-2017-6349](https://insights.sbomify.com/CVE-2017-6349/): Integer overflow in n/a (critical 9.8)
- [CVE-2017-6350](https://insights.sbomify.com/CVE-2017-6350/): Integer overflow in n/a (critical 9.8)
- [CVE-2017-5953](https://insights.sbomify.com/CVE-2017-5953/): Integer overflow in n/a (critical 9.8)
- [CVE-2008-3075](https://insights.sbomify.com/CVE-2008-3075/): Command injection in n/a (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-9389 and fix it if it is affected.

What it is: CVE-2025-9389 is a medium-severity memory corruption vulnerability in Vim Vim, published on 24 Aug 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-2025-9389 exists.

Affected product: Vim Vim. 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-2025-9389/ (Markdown: https://insights.sbomify.com/CVE-2025-9389/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-9389
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-9389
- OSV: https://osv.dev/vulnerability/CVE-2025-9389

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-9389/
Summaries are generated and may contain mistakes; the official description above is the record.