What’s Vulnerable › Vulnerabilities

CVE-2026-76820: OpenCTI: Synchronizer SSRF: stream fetch has no URL validation

• Severity: high (CVSS 7.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-15 · updated 2026-09-30
• Weakness: CWE-918

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.

Affected products

• OpenCTI-Platform opencti: before 7.260701.0

References

• https://github.com/OpenCTI-Platform/opencti/commit/6c1114ce8ce8f3a9d9b8c82dfff3a3a462e5dc1f
• 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-q934

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