OpenctiApplication · Citeum

CVE-2026-21886

HIGH · 8.1 CVSS v3.1 Published 2026-03-17
Fix available
A fix is available. Upgrade to 6.9.1 or later.
See remediation →
87/100
Remediation priority · High
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
OpenCTI is an open source platform for managing cyber threat intelligence knowledge and observables. Prior to version 6.9.1, the GraphQL mutations "IndividualDeletionDeleteMutation" is intended to allow users to delete individual entity objects respectively. However, it was observed that this mutation can be misused to delete unrelated and sensitive objects such as analyses reports etc. This behavior stems from the lack of validation in the API to ensure that the targeted object is contextually related to the mutation being executed. Version 6.9.1 fixes the issue.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

OpenCTI GraphQL API contains an Insecure Direct Object Reference (IDOR) vulnerability in the IndividualDeletionDeleteMutation. The mutation lacks proper authorization validation to verify that the targeted object is contextually related to the individual entity being deleted, allowing attackers to delete unrelated sensitive objects like analysis reports.

MitigationUpgrade OpenCTI to version 6.9.1 or later, which implements contextual validation to ensure deleted objects are properly related to the mutation being executed.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
OpenctiApplication
Affected:< 6.9.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm OpenCTI installation
    Locate the OpenCTI application directory or check running services (e.g., ps aux | grep opencti, docker ps, or systemd service status)
    Affected if OpenCTI is present in the environment
  2. Identify installed OpenCTI version
    Check the version file, container image tag, or query the GraphQL API introspection for version info (typically at /api)
    Affected if Version is less than 6.9.1
  3. Verify GraphQL API is accessible
    Confirm the GraphQL endpoint is reachable (default: /api/graphql) and accepts mutations
    Affected if GraphQL API accepts authenticated or unauthenticated requests
  4. Confirm IndividualDeletionDeleteMutation exists
    Query the GraphQL introspection (query { __schema { mutationType { name fields { name } } } }) to verify the mutation is exposed
    Affected if The mutation is present in the schema without contextual authorization checks

Environment is affected if OpenCTI version is below 6.9.1 and the GraphQL API with the IndividualDeletionDeleteMutation is accessible to the user.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 6.9.1 or later
Fixed in 6.9.1
Interim mitigation

Upgrade OpenCTI to version 6.9.1 or later, which implements contextual validation to ensure deleted objects are properly related to the mutation being executed.

Recommended fix High confidence

6.9.1

  1. Identify the current OpenCTI version running in your environment
  2. Plan for a maintenance window to perform the upgrade
  3. Back up the OpenCTI database and configuration files before upgrading
  4. Upgrade OpenCTI to version 6.9.1 or later by following the official upgrade documentation at https://github.com/OpenCTI-Platform/opencti
  5. Verify the upgrade was successful by checking the version number in the UI or via API
  6. Test that the IndividualDeletionDeleteMutation now properly validates contextual relationships before allowing deletions
  7. Monitor system logs for any unauthorized deletion attempts

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Opencti Scoped from the published advisory
  • Consultation2.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,290
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,664.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-21886 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data