CVE-2026-21887

OpenCTI has a Semi-Blind SSRF via Unvalidated External URL in Data Ingestion Feature

HIGH
7.7
CVSS Score
Published: March 12, 2026 at 05:00 PM UTC
Updated: June 17, 2026 at 10:19 AM UTC
2 products affected across 2 vendorsOpenctiOpencti

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Severity
HIGH7.7
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to 6.8.16, the OpenCTI platform’s data ingestion feature accepts user-supplied URLs without validation and uses the Axios HTTP client with its default configuration (allowAbsoluteUrls: true). This allows attackers to craft requests to arbitrary endpoints, including internal services, because Axios will accept and process absolute URLs. This results in a semi-blind SSRF, as responses may not be fully visible but can still impact internal systems. This vulnerability is fixed in 6.8.16.

Affected

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

v < 6.8.16
v < 6.8.16
Affected range stops below 6.8.16, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

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

StatusANALYZED
CWE
CWE-918

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