CVE-2026-103664: MISP contains a reflected cross-site scripting (XSS) vulnerability in the analyst data notes panel.

MISP contains a reflected cross-site scripting (XSS) vulnerability in the analyst data notes panel.

MISP contains a reflected cross-site scripting (XSS) vulnerability in the analyst data notes panel. The seed path parameter, supplied by the user via the URL, was passed directly into inline JavaScript within the rendered HTML response without any sanitization or type enforcement. An attacker who can convince an authenticated MISP user to navigate to a crafted URL (for example, via a phishing link) can inject arbitrary JavaScript that executes in the victim's browser context. This may allow the attacker to read session tokens, manipulate the page, or perform actions on behalf of the victim. Preconditions: - The victim must be authenticated to MISP and access the analyst data view for an attribute or object. - The attacker must supply a malicious seed value in the URL path. Impact: - Execution of arbitrary JavaScript in the victim's browser session. - Potential theft of session credentials or sensitive data visible in the page. - Manipulation of the analyst data interface. Affected: MISP versions prior to the fix (commit 58925dbf0, post v2.5.48).

Description from the National Vulnerability Database, published by 5a6e4751-2f3f-4070-9419-94fb35b644e8

What it means for a small business

If your business uses MISP, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.30%, higher than 22% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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