What’s Vulnerable › Vulnerabilities
CVE-2026-54393: MISP Overmind theme stored XSS via unvalidated homepage setting
- Severity: medium (CVSS 5.1 v4.0)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-06-12 · updated 2026-06-17
- Weakness: CWE-79
Description
A stored cross-site scripting vulnerability exists in MISP when the Overmind theme is used. The setHomePage endpoint previously saved the user-controlled path value through setSettingInternal(), bypassing the normal setSetting() validation logic, including validate_homepage, which requires homepage paths to start with /. As a result, an authenticated user could store an arbitrary homepage value, including an XSS payload. The stored value was later rendered in app/View/News/index.ctp as the href attribute of the “Continue to homepage” link without HTML escaping. This could allow execution of attacker-controlled JavaScript in the browser context of the affected MISP instance when the crafted homepage link is rendered and interacted with. The issue is fixed by always persisting the homepage setting through setSetting(), ensuring validation and access checks are applied, and by HTML-escaping the homepage value before rendering it in the news view.
Affected products
- MISP: before 2.5.40 — fixed in 2.5.40
How to fix
Upgrade to a fixed version: MISP 2.5.40. Check the vendor advisory for mitigations.
References
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