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

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.047 (91.7th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 92nd percentile — 91.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-27960: rose from 0.020 to 0.047.

EPSS over last 30 days · oldest: 0.020 · newest: 0.047 · change: +0.027

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

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?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.