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…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
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.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-54359 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-54359 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-54359. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-54359 in your dependencies?
O3 detects CVE-2026-54359 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.