CVE-2026-21886 OpenCTI's GraphQL Mutations Allow Deletion of Unrelated Entities
Attackers can delete unrelated sensitive objects via GraphQL mutations due to missing contextual validation in OpenCTI.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-21886?
CVE-2026-21886 is a medium-severity missing authorization vulnerability in OpenCTI-Platform opencti, published on 17 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-21886?
1 open source package ship an affected version, including pycti. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
pycti PyPI | All versions | 6.9.1 |
Products include Citeum Opencti.
How do I fix CVE-2026-21886?
Upgrade pycti to 6.9.1 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-21886 being exploited?
There is no known exploitation of CVE-2026-21886 in the wild and no public exploit code.
Other vulnerabilities in OpenCTI-Platform opencti
- CVE-2026-27960 OpenCTI privilege escalation and unauthenticated access via default admin account
- CVE-2026-39980 OpenCTI affected by RCE via notifier template
- CVE-2025-24977 OpenCTI has remote code execution and sensitive secrets exposed through web hook
- CVE-2024-26139 OpenCTI Authenticated Privilege Escalation
- CVE-2024-45404 OpenCTI's lack of Rate Limit lead to OTP brute forcing
Sources
Also known as GHSA-mhmx-j75v-2m6x, PYSEC-2026-117.