CVE-2026-54393

MISP Overmind theme stored XSS via unvalidated homepage setting

MEDIUM
5.1
CVSS Score
Published: June 12, 2026 at 08:21 PM UTC
Updated: June 17, 2026 at 10:58 AM UTC
1 product affected across 1 vendorMISP

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Severity
MEDIUM5.1
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.5.40
Affected range stops below 2.5.40, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.1MEDIUMCIRCL
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-79

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