Cyber Posture

CVE-2026-27960

Critical

Published: 05 May 2026

Published
05 May 2026
Modified
05 May 2026
KEV Added
Patch
CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0006 17.0th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Description

OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. In versions 6.6.0 through 6.9.12, there is a privilege escalation vulnerability that can be exploited by unauthenticated attackers to query the API as any existing user,…

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including the default admin account. This issue has been fixed in version 6.9.13. As a workaround, the default admin can be disabled using the `APP__ADMIN__EXTERNALLY_MANAGED` configuration.

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-287

Detects unauthorized successful logons resulting from improper authentication implementations.

addresses: CWE-287

Documented procedures ensure personnel are trained on authentication mechanisms, tangibly lowering the risk of improper authentication being exploited.

addresses: CWE-287

Security awareness training instructs users on secure authentication practices and avoiding credential compromise.

addresses: CWE-287

Training on authentication mechanisms and best practices decreases the occurrence of improper authentication.

addresses: CWE-287

Non-repudiation requires strong authentication mechanisms to irrefutably attribute performed actions to specific individuals or processes.

addresses: CWE-287

Session content review can reveal authentication bypasses or failures in session establishment.

addresses: CWE-287

Review of authentication-related audit records can detect improper authentication mechanisms or bypasses.

addresses: CWE-287

Assessments check authentication mechanisms for correct implementation and effectiveness, reducing successful authentication bypass attempts.

Security SummaryAI

CVE-2026-27960 is a privilege escalation vulnerability (CWE-287) in OpenCTI, an open-source platform for managing cyber threat intelligence knowledge and observables. The flaw affects versions 6.6.0 through 6.9.12 and enables unauthenticated attackers to query the API as any existing user, including the default admin account. It carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating critical severity due to its network accessibility, low attack complexity, and lack of prerequisites.

Unauthenticated attackers can exploit this vulnerability remotely without privileges or user interaction. By leveraging the flaw, they can impersonate legitimate users to access sensitive threat intelligence data and observables, potentially leading to unauthorized data exfiltration, manipulation, or disruption of platform availability.

The vulnerability is fixed in OpenCTI version 6.9.13. As a workaround, administrators can disable the default admin account using the `APP__ADMIN__EXTERNALLY_MANAGED` configuration option. Additional details are available in the security advisory at https://github.com/OpenCTI-Platform/opencti/security/advisories/GHSA-6vvv-vmfr-xhrx.

Details

CWE(s)

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1078 Valid Accounts Stealth
Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
T1078.001 Default Accounts Stealth
Adversaries may obtain and abuse credentials of a default account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
Why these techniques?

CVE describes remote unauthenticated auth bypass (CWE-287) on public-facing OpenCTI API allowing impersonation of any user including default admin; directly enables T1190 (exploit public app for initial access), T1068 (exploit for priv esc), and T1078/T1078.001 (abuse valid/default accounts without credentials).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

References