CVE-2026-76820CWE-918ssrf

CVE-2026-76820

High · published September 16, 2026

CVSS v3.1
7.7
EPSS
0%
Percentile
34.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.7 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00415 · 34.7th percentile
Weakness
CWE-918 · Server-Side Request Forgery (SSRF)
Published
2026-09-16T00:17Z
References (4)
EPSS history
Timeline
  • 17 SEP 03:32Z
    EPSS moved — → 0%
    epss
  • 15 SEP 19:40Z
    OpenCTI: Synchronizer SSRF: stream fetch has no URL validation
    cvelistv5