What is CVE-2026-21887?

CVE-2026-21887 is a high-severity vulnerability in Opencti-platform Opencti, classified under Server-Side Request Forgery (SSRF). CVSS score: 7.7/10. Published 2026-03-12.

How severe is CVE-2026-21887?

High severity. CVSS v3 base score is 7.7 out of 10.

SSRF in Opencti-platform Opencti

CVE-2026-21887

OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to 6.8.16, the OpenCTI platform’s data ingestion feature accepts user-supplied URLs without validation and uses the Axios HTTP clien…

Vulnerability class: SSRF (Server-Side Request Forgery)

EPSS: 0.000 (14.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.

Affected products

Opencti-platform Opencti — versions < 6.8.16

Weakness classification (CWE)

CWE-918 — Server-Side Request Forgery (SSRF)

References

https://github.com/OpenCTI-Platform/opencti/security/advisories/GHSA-ffm6-vvph-g5f5 (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-21887?: CVE-2026-21887 is a high-severity vulnerability in Opencti-platform Opencti, classified under Server-Side Request Forgery (SSRF). CVSS score: 7.7/10. Published 2026-03-12.
How severe is CVE-2026-21887?: High severity. CVSS v3 base score is 7.7 out of 10.