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TI-2026-27363 Aliases CVE-2026-35210

OpenCTI: Authorization Bypass via `synchronized-upsert` HTTP Header Injection

Priority LOW 31CWE-639Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
Low · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-639.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00353 29th percentileScored 2026-11-07
Fix Fixed opencti (OpenCTI-Platform): 7.260326.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
OpenCTI-Platformopenctibefore 7.260326.07.260326.0Patch availableCNA
  • opencti VendorOpenCTI-Platform Affected before 7.260326.0 Fixed in 7.260326.0 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:citeum:opencti:*:*:*:*:*:*:*:*before 7.260326.0VulnerableOpenCTI-Platform
  • cpe:2.3:a:citeum:opencti:*:*:*:*:*:*:*:* Versions before 7.260326.0 Vulnerable ·OpenCTI-Platform

Remediation

  • Fix · CNA opencti (OpenCTI-Platform) Fixed in 7.260326.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-35210

References

Patch 2

Advisory 1

Other 1

  • TI-2024-24682 OpenCTI May Bypass Introspection Restriction CVSS 3.1HIGH 8.2
  • TI-2024-30453 OpenCTI's lack of Rate Limit lead to OTP brute forcing CVSS 3.1HIGH 8.1
  • TI-2020-19176 OpenCTI 3.3.1 - Directory Traversal CVSS 4.0HIGH 7.1
  • TI-2026-22303 OpenCTI privilege escalation and unauthenticated access via default admin account CVSS 3.1CRITICAL 9.8
  • TI-2020-19179 OpenCTI 3.3.1 - Cross Site Scripting CVSS 4.0MEDIUM 5.1
  • TI-2024-30771 OpenCTI leaks support information due to inadequate access control CVSS 3.1MEDIUM 4.3
See all 21 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences