CVE-2026-126402

Fleet before 4.89.0 Broken Access Control via User Administration API

Published Nov 13, 2026 CVSS 4.0 · 8.6 High EPSS < 1% KEV · Not listed

Description

Fleet before 4.89.0 contains an incorrect authorization flaw in its user administration API that accepts user creation or modification when the caller administers any one of the assigned teams. Authenticated team administrators can grant users administrator roles on other teams, then deploy software and execute scripts on those teams' hosts.

Analysis

No analysis available yet

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

fleetdm

fleet

unaffected

Version	Status	Constraints
`0`	affected	< 4.89.0
`4.89.0`	unaffected	—

No data.

No data available yet.

Remediation

No remediation available yet

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required High

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required High

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.490% probability within 30 days)

Key SSVC decision points have not yet been added.

References

Link	Providers
https://github.com/fleetdm/fleet/security/advisories/GHSA-mj9p-fq5h-mw8h
https://www.vulncheck.com/advisories/fleet-before-4.89.0-broken-access-control-via-user-administration-api

History

Nov 13, 2026 9:45 AM Description updated. Title updated. First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		Fleet before 4.89.0 contains an incorrect authorization flaw in its user administration API that accepts user creation or modification when the caller administers any one of the assigned teams. Authenticated team administrators can grant users administrator roles on other teams, then deploy software and execute scripts on those teams' hosts.
Title		Fleet before 4.89.0 Broken Access Control via User Administration API
First Time appeared		Fleetdm Fleetdm fleet
Weaknesses		CWE-863
CPEs		cpe:2.3:a:fleetdm:fleet::::::::
Vendors & Products		Fleetdm Fleetdm fleet
References		https://github.com/fleetdm/fleet/security/advisories/GHSA-mj9p-fq5h-mw8h https://www.vulncheck.com/advisories/fleet-before-4.89.0-broken-access-control-via-user-administration-api
Metrics		cvssV3_1 `{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H'}` cvssV4_0 `{'score': 8.6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}`