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 an

highCVSS 7.1CVE-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.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: high — CVSS 7.1
Published: 2026-07-08
Last updated: 2026-07-10
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-35210

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-352100.27% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 19% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-35210	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

medium[UPDATE] [medium] OpenCTI: Vulnerability allows bypassing security measurescert-bund

Recent advisories for OpenCTI is an

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

medium[NEW] [medium] OpenCTI: Vulnerability allows Denial of Servicecert-bund · 2026-07-09
medium[UPDATE] [medium] OpenCTI: Vulnerability allows bypassing security measurescert-bund · 2026-07-09
mediumCVE-2026-35211: OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observ…nvd · 2026-07-08