OpenClaw versions older than 2026.2.23 contain a stored cross‑site scripting flaw (CWE‑79) in the HTML session exporter. Attackers can embed malicious MIME type strings in image content blocks, which break out of the img src data‑URL context when the session is exported to HTML. This injection allows arbitrary JavaScript to run in the victim’s browser when the generated HTML is opened, enabling cookie theft, session hijacking, or other client‑side attacks.

The vulnerability affects the OpenClaw product from OpenClaw. All releases before 2026.2.23 are impacted; administrators should verify the installed version and expose any installations below the patched release for remediation.

The CVSS score for this flaw is 2.4, indicating low severity, and no EPSS score is available. The flaw is not listed in the CISA KEV catalog. Exploitation requires an attacker to craft a malicious session entry with a forged MIME type and have a user open the resulting exported HTML file, so the attack vector is user interaction with a local file. Given the low score, widespread exploitation is unlikely, but vulnerable systems should be updated promptly to eliminate the risk.