# CVE-2026-10278: ishayoyo excel-mcp read_file/write_file index.ts path traversal

> Remote attackers can exploit path traversal in the excel-mcp library to read or modify arbitrary files via manipulated file path arguments.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Jun 2026
- **Updated:** 2 Jun 2026
- **Also known as:** GHSA-vgmg-2m2p-qqqj

## What is CVE-2026-10278?

CVE-2026-10278 is a medium-severity path traversal vulnerability in ishayoyo excel-mcp, published on 1 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was determined in ishayoyo excel-mcp up to 1.0.2. Impacted is an unknown function of the file src/index.ts of the component read_file/write_file. Executing a manipulation of the argument filePath/outputPath can lead to path traversal. It is possible to launch the attack remotely. The exploit has been publicly disclosed and may be utilized. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-10278?


## How do I fix CVE-2026-10278?

No fix has been published for CVE-2026-10278 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-10278 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-10278 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-10278 and fix it if it is affected.

What it is: CVE-2026-10278 is a medium-severity path traversal vulnerability in ishayoyo excel-mcp, published on 1 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-10278 exists.

Affected product: ishayoyo excel-mcp. 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-2026-10278/ (Markdown: https://insights.sbomify.com/CVE-2026-10278/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-10278
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-10278
- OSV: https://osv.dev/vulnerability/CVE-2026-10278

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-10278/
Summaries are generated and may contain mistakes; the official description above is the record.