Is CVE-2026-21886 in the CISA KEV catalog?

No. CVE-2026-21886 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-21886?

CVE-2026-21886 has a CVSS v3 base score of 6.5 (MEDIUM).

What is the EPSS score for CVE-2026-21886?

CVE-2026-21886 has an EPSS score of 0.23% (13th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-21886?

Upgrade opencti to 6.9.1 or later.

CVE & CISA-KEV Catalog

CVE-2026-21886

MEDIUM

6.5

CVSS v3

NVD

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.

CWE-285 CWE-566 CWE-915

How to fix

Remediation Available

openctiNVD

Affected:< 6.9.1Fixed in:6.9.1CVE-2026-21886derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

0.23%probability of exploitation in 30 days

13thpercentile

Low risk: more likely to be exploited than 13% of all known CVEs.

References

Vendor Advisory1

github.com

Embed a live status badge for CVE-2026-21886

Markdown

[![CVE-2026-21886](https://tridentstack.com/cve/badge/CVE-2026-21886.svg)](https://tridentstack.com/cve/CVE-2026-21886)

HTML

<a href="https://tridentstack.com/cve/CVE-2026-21886"><img src="https://tridentstack.com/cve/badge/CVE-2026-21886.svg" alt="CVE-2026-21886"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-03-19.