# CVE-2026-100538: OpenClaw before 2026.8.1 Local File Read via Outbound Attachments

> Attackers can read local files by bypassing sender tool restrictions in OpenClaw, exposing sensitive data to unauthorized requesters.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Sep 2026
- **Updated:** 28 Sep 2026
- **Also known as:** GHSA-m2g4-5ff5-4cf5, GHSA-w5x7-c87m-3jpc, MINI-hmj2-92g5-v7hv

## What is CVE-2026-100538?

CVE-2026-100538 is a high-severity missing authorization vulnerability in OpenClaw, published on 26 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

OpenClaw (npm package 'openclaw') before 2026.8.1 does not apply the originating sender's global or per-agent toolsBySender policy when handling outbound attachments. A sender that has been explicitly denied filesystem read tools can still cause a known local file to be read and returned via a final-response media directive or a message attachment, disclosing local file contents to an admitted requester whose agent turn did not include the read tool. Exploitation requires knowledge or derivation of a useful host path and a delivery flow that accepts local attachments. The issue is fixed in version 2026.8.1.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-100538?


## How do I fix CVE-2026-100538?

Upgrade to a fixed version.

## Is CVE-2026-100538 being exploited?

There is no known exploitation of CVE-2026-100538 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-100538 and fix it if it is affected.

What it is: CVE-2026-100538 is a high-severity missing authorization vulnerability in OpenClaw, published on 26 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-100538 in the wild and no public exploit code.

Affected product: OpenClaw. 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-2026-100538/ (Markdown: https://insights.sbomify.com/CVE-2026-100538/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-100538
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-100538
- OSV: https://osv.dev/vulnerability/CVE-2026-100538

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-100538/
Summaries are generated and may contain mistakes; the official description above is the record.