CVE-2026-35210

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.

CVSS 3.1

7.1CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

EPSS

0.4% chance of exploitation in the next 30 days; higher than 28% of CVEs (scores of 2026-10-25)

CWEs

CWE-639, CWE-863

Published

2026-07-08

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

Affected

• citeum:opencti

Packages (OSV)

References

• https://github.com/OpenCTI-Platform/opencti/commit/134531ddf5ecf741006b7f0870b7c36711b96540
• https://github.com/OpenCTI-Platform/opencti/pull/14243
• https://github.com/OpenCTI-Platform/opencti/releases/tag/7.260326.0
• https://github.com/OpenCTI-Platform/opencti/security/advisories/GHSA-36fr-4m54-94mj

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