# CVE-2026-6635: rowboatlabs rowboat tools_webhook app.py tool_call improper authentication

> Remote attackers can bypass authentication in the rowboat tools_webhook component by manipulating the X-Tools-JWE header.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Apr 2026
- **Updated:** 20 Apr 2026
- **Also known as:** GHSA-6c34-3mhj-jwxw

## What is CVE-2026-6635?

CVE-2026-6635 is a medium-severity authentication bypass vulnerability in rowboatlabs rowboat, published on 20 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A security vulnerability has been detected in rowboatlabs rowboat up to 0.1.67. This impacts the function tool_call of the file apps/experimental/tools_webhook/app.py of the component tools_webhook. Such manipulation of the argument X-Tools-JWE leads to improper authentication. The attack may be performed from remote. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-6635?


## How do I fix CVE-2026-6635?

No fix has been published for CVE-2026-6635 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-6635 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-6635 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-6635 and fix it if it is affected.

What it is: CVE-2026-6635 is a medium-severity authentication bypass vulnerability in rowboatlabs rowboat, published on 20 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-6635 exists.

Affected product: rowboatlabs rowboat. 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-2026-6635/ (Markdown: https://insights.sbomify.com/CVE-2026-6635/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-6635
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-6635
- OSV: https://osv.dev/vulnerability/CVE-2026-6635

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-6635/
Summaries are generated and may contain mistakes; the official description above is the record.