published October 1, 2026
MISP contains a reflected cross-site scripting (XSS) vulnerability in the legacy taxonomy tag management confirmation forms (add tag and disable tag).
The affected forms echoed a user-supplied tag name value from the request unescaped into the rendered HTML output. An attacker who can induce a site administrator to visit a crafted URL containing a malicious tag name parameter can execute arbitrary JavaScript in the administrator's browser session.
Preconditions:
- The target must be running a MISP instance with the legacy taxonomy tag confirmation views enabled.
- The victim must be an authenticated site administrator.
- The victim must navigate to the attacker-crafted URL (e.g., via a phishing link).
Security impact:
- Execution of arbitrary client-side script in the context of the administrator's browser.
- Potential theft of session tokens, CSRF tokens, or other sensitive data accessible from the page.
- Potential for performing privileged actions on behalf of the administrator within the MISP interface.
Affected versions: <2.5.48.