Vulnerability Description
OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to 7.260701.0, the synchronizerFetch GraphQL query called fetchRemoteStreams after checking only that a remote stream URL used HTTP or HTTPS. The backend did not apply the ingestion deny list or reject private, loopback, and link-local destinations, allowing an authenticated account with the INGESTION capability to make OpenCTI request internal services and cloud metadata endpoints. Returned connection errors could distinguish open HTTP ports, open non-HTTP ports, and closed ports, enabling internal network scanning, while compatible endpoint responses could disclose internal data. This issue is fixed in version 7.260701.0.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/OpenCTI-Platform/opencti/commit/6c1114ce8ce8f3a9d9b8c82dfff3a
- https://github.com/OpenCTI-Platform/opencti/pull/16617
- https://github.com/OpenCTI-Platform/opencti/releases/tag/7.260701.0
- https://github.com/OpenCTI-Platform/opencti/security/advisories/GHSA-f6pj-3m32-q
FAQ
What is CVE-2026-76820?
CVE-2026-76820 is a vulnerability with a CVSS score of 7.7 (HIGH). OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to 7.260701.0, the synchronizerFetch GraphQL query called fetchRemoteStreams after checking o...
How severe is CVE-2026-76820?
CVE-2026-76820 has been rated HIGH with a CVSS base score of 7.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-76820?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.