CVE-2026-35210: OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables

Q: How do I fix CVE-2026-35210?

opencti: upgrade to 7.260326.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-35210 being exploited?

CVE-2026-35210 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-35210 affect?

CVE-2026-35210 affects opencti. Severity is high (CVSS 7.1). 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 b

Routine

HIGH 7.1UPGRADE

CVE-2026-35210 is a high-severity flaw (CVSS 7.1) affecting opencti. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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:

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.1 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 71%)
CISA exploited list	No
Weakness	CWE-639, CWE-863
Published	2026-07-08
Last modified	2026-10-25

Publisher (CNA): GitHub, Inc. · Vendor: citeum

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-08 21:16 UTCPublished CVE record published
2026-10-25 17:10 UTCUpdated Record last modified

citeum opencti UPGRADE

Affected: < 7.260326.0

Fixed in: 7.260326.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy opencti || rpm -q opencti || opencti --version

2. UPGRADE to 7.260326.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade opencti

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade opencti

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-35210?

opencti: upgrade to 7.260326.0. Exact commands for each OS are on this page.

Is CVE-2026-35210 being exploited?

CVE-2026-35210 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-35210 affect?

CVE-2026-35210 affects opencti. Severity is high (CVSS 7.1). 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 b

How urgent is CVE-2026-35210?

Priority 32/100. High severity

Related CVEs

CVE-2026-35211 MEDIUM 6.5 UPGRADE OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables

References

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