Auth bypass in Citeum Opencti
CVE-2026-21886
OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to version 6.9.1, the GraphQL mutations "IndividualDeletionDeleteMutation" is intended to allow users to delete individual entity objects respectively. However, it was observed that this mutation can be misused to delete unrelated and sensitive objects such as analyses reports etc. This behavior stems from the lack of validation in the API to ensure that the targeted object is contextually related to the mutation being executed. Version 6.9.1 fixes the issue.
EPSS: 0.002 (13.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Citeum Opencti
- Opencti-platform Opencti — versions < 6.9.1
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-21886?
- CVE-2026-21886 is a medium-severity vulnerability in Citeum Opencti, classified under Improper Authorization. CVSS score: 6.5/10. Published 2026-03-17.
- How severe is CVE-2026-21886?
- Medium severity. CVSS v3 base score is 6.5 out of 10.