# CVE-2026-59857: Vim: Out-of-bounds Write in SAL Soundfolding

> A boundary error in Vim's spell checker allows a stack buffer overflow, potentially crashing the editor when processing specific words with SAL rules.

- **Severity:** Medium 5.6 (`CVSS:4.0/AV:L/AC:L/AT:P/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:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 9 Jul 2026
- **Updated:** 10 Jul 2026
- **Also known as:** ALPINE-CVE-2026-59857, BELL-CVE-2026-59857, CLSA-2026-1784189693, CLSA-2026-1784800448, DEBIAN-CVE-2026-59857, ECHO-835b-eaa6-823f, GHSA-m3hf-xcm3-xhm2, MINI-c24r-gj9j-9rw2, UBUNTU-CVE-2026-59857

## What is CVE-2026-59857?

CVE-2026-59857 is a medium-severity memory corruption vulnerability in Vim Vim, published on 9 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Vim is an open source, command line text editor. Prior to 9.2.0725, the single-byte branch of spell_soundfold_sal() in src/spell.c translates a word through a spell file's SAL sound-folding rules into a caller-owned result buffer, but its result writes are guarded with reslen < MAXWLEN, allowing reslen to reach MAXWLEN before res[reslen] = NUL writes one byte past the end of the MAXWLEN-element stack buffer. A boundary-length word passed to soundfold(), or reached via sound-based spell suggestion while a SAL-based spell language is active under a non-multibyte 8-bit encoding, can corrupt the eval_soundfold() stack frame and crash the editor. This issue is fixed in version 9.2.0725.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-59857?

It affects 1 product.


Products: Vim Vim.

## How do I fix CVE-2026-59857?

Upgrade to a fixed version.

## Is CVE-2026-59857 being exploited?

There is no known exploitation of CVE-2026-59857 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-2026-59857 and fix it if it is affected.

What it is: CVE-2026-59857 is a medium-severity memory corruption vulnerability in Vim Vim, published on 9 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-59857 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-2026-59857/ (Markdown: https://insights.sbomify.com/CVE-2026-59857/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-59857
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-59857
- OSV: https://osv.dev/vulnerability/CVE-2026-59857

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-59857/
Summaries are generated and may contain mistakes; the official description above is the record.