CVE-2026-21887
OpenCTI has Semi-Blind SSRF via Unvalidated External URL in Data Ingestion Feature
Description
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 client with its default configuration (allowAbsoluteUrls: true). This allows attackers to craft requests to arbitrary endpoints, including internal services, because Axios will accept and process absolute URLs. This results in a semi-blind SSRF, as responses may not be fully visible but can still impact internal systems. This vulnerability is fixed in 6.8.16.
How to fix CVE-2026-21887
To remediate CVE-2026-21887, upgrade the affected package to a fixed version below.
- —upgrade to 6.8.16 or later
- —upgrade to 6.8.16 or later
Is CVE-2026-21887 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 6.8.16
- from 0, < 6.8.16
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |