CVE-2026-35210
OpenCTI: Authorization Bypass via `synchronized-upsert` HTTP Header Injection
Description
OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to 7.260326.0, an authorization bypass vulnerability in OpenCTI allows any authenticated user with KNOWLEDGE_KNUPDATE permission to bypass Confidence Level validation and Object Marking restrictions by injecting the synchronized-upsert: true HTTP header, enabling attackers to downgrade confidence levels, remove security markings such as TLP:RED, manipulate relationships, and affect STIX object types including Indicators, ThreatActors, Malware, and Reports. This issue is fixed in version 7.260326.0.
INFO
Published Date :
July 8, 2026, 9:16 p.m.
Last Modified :
Oct. 25, 2026, 5:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update OpenCTI to version 7.260326.0.
- Remove KNOWLEDGE_KNUPDATE permission if not needed.
- Validate HTTP headers for unauthorized modifications.
- Review existing object markings and confidence levels.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-35210.
| URL | Resource |
|---|---|
| https://github.com/OpenCTI-Platform/opencti/commit/134531ddf5ecf741006b7f0870b7c36711b96540 | Patch |
| https://github.com/OpenCTI-Platform/opencti/pull/14243 | Issue Tracking Patch |
| https://github.com/OpenCTI-Platform/opencti/releases/tag/7.260326.0 | Product Release Notes |
| https://github.com/OpenCTI-Platform/opencti/security/advisories/GHSA-36fr-4m54-94mj | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-35210 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-35210
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-35210 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-35210 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 25, 2026
Action Type Old Value New Value Added Translation Title: opencti de OpenCTI-Platform, Description: OpenCTI es una plataforma de código abierto para gestionar el conocimiento y los observables de inteligencia de ciberamenazas. Antes de la versión 7.260326.0, una vulnerabilidad de omisión de autorización en OpenCTI permite a cualquier usuario autenticado con permiso KNOWLEDGE_KNUPDATE omitir la validación del Nivel de Confianza y las restricciones de Marcado de Objetos inyectando el encabezado HTTP synchronized-upsert: true, lo que permite a los atacantes degradar los niveles de confianza, eliminar marcados de seguridad como TLP:RED, manipular relaciones y afectar tipos de objetos STIX incluyendo Indicadores, Actores de Amenazas, malware y Reportes. Este problema está solucionado en la versión 7.260326.0. -
Initial Analysis by [email protected]
Jul. 13, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:citeum:opencti:*:*:*:*:*:*:*:* versions up to (excluding) 7.260326.0 Added Reference Type GitHub, Inc.: https://github.com/OpenCTI-Platform/opencti/commit/134531ddf5ecf741006b7f0870b7c36711b96540 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/OpenCTI-Platform/opencti/pull/14243 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/OpenCTI-Platform/opencti/releases/tag/7.260326.0 Types: Product, Release Notes Added Reference Type GitHub, Inc.: https://github.com/OpenCTI-Platform/opencti/security/advisories/GHSA-36fr-4m54-94mj Types: Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 09, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-35210', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-09T13:45:35.902145Z'} -
New CVE Received by [email protected]
Jul. 08, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'OpenCTI-Platform', 'product': 'opencti', 'versions': [{'status': 'affected', 'version': '< 7.260326.0'}]}] Added Description OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to 7.260326.0, an authorization bypass vulnerability in OpenCTI allows any authenticated user with KNOWLEDGE_KNUPDATE permission to bypass Confidence Level validation and Object Marking restrictions by injecting the synchronized-upsert: true HTTP header, enabling attackers to downgrade confidence levels, remove security markings such as TLP:RED, manipulate relationships, and affect STIX object types including Indicators, ThreatActors, Malware, and Reports. This issue is fixed in version 7.260326.0. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N Added CWE CWE-639 Added CWE CWE-863 Added Reference https://github.com/OpenCTI-Platform/opencti/commit/134531ddf5ecf741006b7f0870b7c36711b96540 Added Reference https://github.com/OpenCTI-Platform/opencti/pull/14243 Added Reference https://github.com/OpenCTI-Platform/opencti/releases/tag/7.260326.0 Added Reference https://github.com/OpenCTI-Platform/opencti/security/advisories/GHSA-36fr-4m54-94mj