CVE-2026-100538
Received Received - Intake

OpenClaw npm Package Local File Read via Attachment Handling

Publication date: 2026-09-26

Last updated on: 2026-09-26

Assigner: VulnCheck

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.

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Meta Information

Published
2026-09-26
Last Modified
2026-09-26
Generated
2026-09-26
AI Q&A
2026-09-26
EPSS Evaluated
N/A
NVD
CVE-2026-100538
EUVD
EUVD-2026-87512

Affected Vendors & Products

Currently, no data is known.

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-863 The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

Attack-Flow Graph

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Executive Summary

OpenClaw before version 2026.8.1 fails to enforce filesystem read restrictions set by the sender when handling outbound attachments. Even if a sender is explicitly denied filesystem read tools, the system may still read and disclose local file contents through attachments or media directives. This bypasses intended security policies.

Detection Guidance

Detecting this vulnerability requires checking if your OpenClaw instance is running a vulnerable version (before 2026.8.1) and verifying if outbound attachments are enabled for restricted agents. Inspect the package version using npm list openclaw or checking the installed version in your application logs. Review agent policies to confirm if toolsBySender read denials are properly enforced for outbound attachments.

Impact Analysis

An attacker with knowledge of a local file path could exploit this to read sensitive files on your system. This could lead to unauthorized access to confidential data, such as documents or configuration files, if your system uses OpenClaw for message handling.

Compliance Impact

This vulnerability could lead to unauthorized disclosure of personal or sensitive data, violating GDPR's data protection principles or HIPAA's requirements for safeguarding protected health information. Organizations using OpenClaw may face compliance violations and potential penalties.

Mitigation Strategies
  • Upgrade the openclaw package to version 2026.8.1 or later to address the vulnerability.
  • Disable local outbound attachments for restricted agents to prevent unauthorized file reads.
  • Store artifacts in non-sensitive directories to reduce the impact of potential file disclosure.
  • Avoid relying solely on toolsBySender read denials as a security boundary for attachments.

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