Medium severity · published Jun 12, 2026
CVE-2026-54393
MISP Overmind theme stored XSS via unvalidated homepage setting
5.1
CVSS
0.4%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 32% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MI
misp · misp
before 2.5.40 · source: vendor
Affected product
MI
misp
misp
More from misp
10.0
CVE-2026-10611
OTP bypass via plugin-based LDAP authentication in MISP when LDAP mixed authentication is enabled
9.8
CVE-2026-85216
MISP LDAP and LinOTP Authentication Bypass via Empty or Invalid Credentials
9.6
CVE-2026-39962
LDAP injection in MISP ApacheAuthenticate when using a user-controlled Apache environment variable
9.4
CVE-2026-56422
MISP Core: Mass Assignment and Object Re-ownership via Unvalidated Request Fields
9.3
CVE-2026-103655
MISP TOTP Code Replay Allows Duplicate Authentication Within Validity Period