Openclaw cli: OpenClaw Vulnerable to HTML injection via unvalidated image MIME type in data-URL interpolation (CVE-2026-32040)

The OpenClaw CLI's HTML session exporter (`src/auto-reply/reply/export-html/template.js`) directly interpolates the `img.mimeType` value into `<img src="data:...">` attributes without validation or escaping. An attacker controlling image entries in session data can craft a MIME type such as `image/png" onerror="alert(document.domain)` to break out of the attribute context and execute arbitrary JavaScript when the exported HTML is opened. This XSS vulnerability requires control over image content blocks but is straightforward to exploit. The issue affects versions >=2026.1.29 and <2026.2.23. The vendor fixed the issue by introducing a `sanitizeImageMimeType()` function that validates MIME types against a whitelist and falls back to `application/octet-stream` for invalid values, preventing attribute breakout.

An attacker with the ability to manipulate image MIME types in session data can execute arbitrary JavaScript in the context of the exported HTML file, resulting in a cross-site scripting (XSS) vulnerability. This can lead to information disclosure or other client-side impacts when the exported HTML is viewed. The vulnerability requires local or limited privileges (AV:L, PR:L) and user interaction (UI:R) to open the exported HTML. The CVSS score is 4.6 (medium severity).

A patch is available and has been applied in versions 2026.2.23 and later. The fix involves sanitizing the image MIME type against a whitelist and defaulting to a safe MIME type for unrecognized values, preventing attribute injection. Users should upgrade to version 2026.2.23 or later to remediate this vulnerability.