OpenClaw has stored XSS in exported session HTML viewer via markdown/raw-HTML rendering

Summary

The exported session HTML viewer allowed stored XSS when untrusted session content included raw HTML markdown tokens or unescaped metadata fields.

Impact

Opening a crafted exported HTML session could execute attacker-controlled JavaScript in the viewer context. This can expose session content in the page and enable phishing or UI spoofing in the trusted export view.

Affected Packages / Versions

• Package: openclaw (npm)
• Affected versions: <= 2026.2.22-2
• Patched version (released): >= 2026.2.23

Technical Details

The exporter rendered markdown with marked.parse(...) and inserted HTML via innerHTML, but did not override the html renderer token path. Raw HTML (for example <img ... onerror=...>) was passed through. Additional tree/header metadata fields were interpolated without escaping in the export template.

Reproduction

1. Create a session containing content like <img src=x onerror=alert(1)>.
2. Export the session to HTML.
3. Open the exported file.
4. Observe script execution from injected content.

Remediation

• Added a marked html(token) renderer override that escapes raw HTML tokens.
• Escaped previously unescaped tree/header metadata fields in the export template.
• Added image MIME sanitization for exported data-URL image rendering.
• Added regression tests for markdown/token and metadata escaping paths.

Fix Commit(s)

• f8524ec77a3999d573e6c6b8a5055bf35c49a2e6

Release Process Note

patched_versions is pre-set to the released version (>= 2026.2.23). This advisory now reflects released fix version 2026.2.23.

OpenClaw thanks @allsmog for reporting.