Auth bypass in Citeum Opencti
CVE-2026-27960
OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. In versions 6.6.0 through 6.9.12, there is a privilege escalation vulnerability that can be exploited by unauthenticated attackers to query the API as any existing user, including the default admin account. This issue has been fixed in version 6.9.13. As a workaround, the default admin can be disabled using the `APP__ADMIN__EXTERNALLY_MANAGED` configuration.
Vulnerability class: Broken Authentication
EPSS: 0.006 (45.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Citeum Opencti
- Opencti-platform Opencti — versions >= 6.6.0, < 6.9.13
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-27960?
- CVE-2026-27960 is a critical-severity vulnerability in Citeum Opencti, classified under Improper Authentication. CVSS score: 9.8/10. Published 2026-05-05.
- How severe is CVE-2026-27960?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2026-27960 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.