CVE-2026-54359

CVE-2026-54359 is a high-severity vulnerability with a CVSS 4.0 base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-352.

Key facts

Description

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.

Frequently asked questions

What is CVE-2026-54359?
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.
How severe is CVE-2026-54359?
CVE-2026-54359 has a CVSS 4.0 base score of 7.1, rated high severity.
Is CVE-2026-54359 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-54359?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-54359 have an EU (EUVD) identifier?
Yes. CVE-2026-54359 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-36551.
When was CVE-2026-54359 published?
CVE-2026-54359 was published on 2026-06-12 and last updated on 2026-06-17.

References

Other CWE-352 (Cross-Site Request Forgery (CSRF)) vulnerabilities

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