CVE-2026-35210: opencti before 7.260326.0 (exclusive), < 7.260326.0

Affected technology

opencti · before 7.260326.0 (exclusive)
citeum

opencti · < 7.260326.0
OpenCTI-Platform

Component: Not specified by the source

Attack conditions (Vendor/CNA, CVSS 3.1): Network (remote) · Low privileges required · No user interaction required

What an attacker can do

Any authenticated user with KNOWLEDGE_KNUPDATE permission can 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. Vendor/CNA’s CVSS 3.1 assessment (base score 7.1/10) rates confidentiality impact as low; integrity impact as high; availability impact as none.