CVE-2026-76820

HIGH 7.7

OpenCTI: Synchronizer SSRF: stream fetch has no URL validation

CVSS Score

7.7

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-918
Vendor	opencti-platform
Product	opencti
Published	Sep 15, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

None

Availability

None

Affected Versions

OpenCTI-Platform / opencti

< 7.260701.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/OpenCTI-Platform/opencti/security/advisories/GHSA-f6pj-3m32-q934 github.com: https://github.com/OpenCTI-Platform/opencti/pull/16617 github.com: https://github.com/OpenCTI-Platform/opencti/commit/6c1114ce8ce8f3a9d9b8c82dfff3a3a462e5dc1f github.com: https://github.com/OpenCTI-Platform/opencti/releases/tag/7.260701.0