CVE Catalog

CVE-2026-85547

MediumCVSS 6.2
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.34%

27th percentile - higher than 27% of all known CVEs

Summary

A CSRF vulnerability exists in MISP due to form-security and CSRF protections being disabled based on REST request detection, which can be influenced by request properties like the Accept header. An attacker can craft cross-origin requests that are treated as REST traffic, bypassing CSRF protection for session-authenticated requests. The fix restricts exemptions to requests carrying a MISP API key and adds support for X-CSRF-Token header.

Risk Assessment

An attacker can trick an authenticated MISP user into visiting a malicious page, enabling unauthorized state-changing operations (modification, creation, publication, deletion) with the victim's privileges. This could compromise data integrity and confidentiality within the organization.

Recommendation

Update MISP to a patched version immediately, where CSRF exemptions are granted only for API-key-authenticated requests. Also ensure support for the X-CSRF-Token header for legitimate same-origin AJAX requests.

Other vulnerabilities in MISP

See all
Original NVD description (English source)

A cross-site request forgery (CSRF) vulnerability exists in MISP due to form-security and CSRF protections being disabled based on whether an incoming request was identified as a REST request. MISP's REST detection can be influenced by request properties such as the URL suffix or the HTTP Accept header. Because Accept: application/json can be supplied by a cross-origin page without requiring a CORS preflight, an attacker could cause a request originating from another website to be treated as REST traffic. MISP would consequently disable its normal form-security and CSRF validation even though the request was authenticated using the victim's existing browser session. An unauthenticated remote attacker could exploit this behavior by convincing an authenticated MISP user to visit or interact with a malicious web page. The attacker's page could then issue crafted requests to susceptible state-changing MISP endpoints using the victim's privileges. Depending on the permissions of the victim and the targeted endpoint, this could allow unauthorized modification, creation, publication, or removal of data and other state changes. The vulnerability originates from granting the form-security exemption based on _isRest() rather than on the authentication mechanism used by the request. The patch changes this behavior so that CSRF and form-security exemptions are granted only when the request actually carries a MISP API key. Session-authenticated REST-style requests remain subject to CSRF protection. The fix also introduces support for transmitting CSRF tokens through the X-CSRF-Token header for legitimate same-origin AJAX requests. Such a header cannot normally be attached by a cross-origin page without triggering a CORS preflight, preventing it from being used to reproduce the original attack.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS