CVE-2026-76820

OpenCTI: Synchronizer SSRF: stream fetch has no URL validation

HIGH
7.7
CVSS Score
Published: September 15, 2026 at 07:40 PM UTC
Updated: September 30, 2026 at 05:43 PM UTC
1 product affected across 1 vendorOpencti

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Severity
HIGH7.7
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 7.260701.0
Affected range stops below 7.260701.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.7HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-918

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