CVE-2026-66421

Received Received - Intake

Stored XSS in OpenClaw Dashboard via Agent Transcript Messages

Publication date: 2026-07-30

Last updated on: 2026-07-30

Assigner: VulnCheck

Description

OpenClaw Dashboard contains a stored cross-site scripting vulnerability that allows unauthenticated remote attackers to execute arbitrary JavaScript in the administrator's browser session by injecting HTML markup into agent transcript messages processed through the sessions API. Attackers can craft a message containing inline event handler payloads such as an img tag with an onerror attribute within the 60-character rendering budget, which is stored in the session transcript and interpolated unsanitized into innerHTML on the default landing page, allowing theft of session tokens and unauthorized calls to authenticated administrative endpoints including agent instruction file modification.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-07-30

Last Modified

2026-07-30

Generated

2026-07-31

AI Q&A

2026-07-31

EPSS Evaluated

N/A

NVD

CVE-2026-66421

EUVD

EUVD-2026-51337

Affected Vendors & Products

Currently, no data is known.

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-79	The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Attack-Flow Graph

Executive Summary

OpenClaw Dashboard has a stored cross-site scripting (XSS) flaw. Unauthenticated attackers can inject malicious JavaScript into agent transcript messages via the sessions API. The payload is stored and later rendered unsanitized in the administrator's browser, enabling session token theft and unauthorized administrative actions.

Detection Guidance

Detecting this vulnerability requires checking for stored XSS in agent transcript messages. Inspect server logs for suspicious HTML markup or event handlers like onerror in session transcripts. Review the sessions API responses for unsanitized user input. No specific commands are provided in the context.

Impact Analysis

Attackers could steal session tokens, impersonate administrators, or modify agent instruction files. This could lead to full system compromise, data breaches, or unauthorized changes to sensitive configurations.

Compliance Impact

This vulnerability could violate GDPR (data protection) and HIPAA (health data security) by enabling unauthorized access to sensitive data. It may lead to non-compliance due to insufficient protection against XSS attacks, potentially resulting in fines or legal consequences.

Mitigation Strategies

Immediately sanitize all user input in agent transcript messages before storage. Implement strict output encoding to prevent HTML/JS injection. Restrict access to the sessions API and monitor for unauthorized administrative actions. Update OpenClaw Dashboard to the latest patched version if available.

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