# CVE-2025-55157: Vim heap use-after-free vulnerability when processing recursive tuple data types

> A use-after-free in Vim allows attackers to cause memory corruption and potentially execute code by tricking users into running malicious Vim scripts.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 11 Aug 2025
- **Updated:** 12 Aug 2025
- **Also known as:** BELL-CVE-2025-55157, GHSA-3r4f-mm4w-wgg6

## What is CVE-2025-55157?

CVE-2025-55157 is a medium-severity use after free vulnerability in Vim Vim, published on 11 Aug 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Vim is an open source, command line text editor. In versions from 9.1.1231 to before 9.1.1400, When processing nested tuples in Vim script, an error during evaluation can trigger a use-after-free in Vim’s internal tuple reference management. Specifically, the tuple_unref() function may access already freed memory due to improper lifetime handling, leading to memory corruption. The exploit requires direct user interaction, as the script must be explicitly executed within Vim. This issue has been patched in version 9.1.1400.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2025-55157?

It affects 1 product.


Products: Vim Vim.

## How do I fix CVE-2025-55157?

Apply the vendor's patch.

## Is CVE-2025-55157 being exploited?

There is no known exploitation of CVE-2025-55157 in the wild and no public exploit code.

## 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-2025-55157 and fix it if it is affected.

What it is: CVE-2025-55157 is a medium-severity use after free vulnerability in Vim Vim, published on 11 Aug 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2025-55157 in the wild and no public exploit code.

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-2025-55157/ (Markdown: https://insights.sbomify.com/CVE-2025-55157/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-55157
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-55157
- OSV: https://osv.dev/vulnerability/CVE-2025-55157

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-55157/
Summaries are generated and may contain mistakes; the official description above is the record.