CVE-2026-21887
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
Is CVE-2026-21887 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- 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 |