CVE-2026-54359MISP contains an insecure default configuration in which the Security.check_sec_fetch_site_header control is disabled.

MISP contains an insecure default configuration in which the Security.check_sec_fetch_site_header control is disabled. When this setting is disabled, state-changing requests such as POST, PUT, or AJAX requests are not restricted based on the browser-provided Sec-Fetch-Site header. A remote unauthenticated attacker could craft a malicious web page that causes an authenticated MISP user’s browser to issue cross-site requests to MISP automation endpoints. If successful, the forged requests may be processed with the privileges of the victim user, potentially allowing unauthorized modification of MISP data or configuration. Enabling Security.check_sec_fetch_site_header mitigates this issue, although operators of multi-homed MISP deployments should validate the setting before enforcing it.

CVSS

7.1 HIGH (v4.0, NVD)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Weakness (CWE)

CWE-352, CWE-1188

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

Not given

NVD analysis

Deferred

Record last updated

Jun 17, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.