fleetdm Fleet up to 4.88.x User Administration API improper authorization

Summaryinfo

A vulnerability has been found in fleetdm Fleet up to 4.88.x and classified as problematic. The impacted element is an unknown function of the component User Administration API. The manipulation leads to improper authorization. This vulnerability is uniquely identified as CVE-2026-126402. The attack is possible to be carried out remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in fleetdm Fleet up to 4.88.x. This issue affects an unknown part of the component User Administration API. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-126402 since 11/10/2026. The exploitation is known to be easy. The attack may be initiated remotely. Additional levels of successful authentication are required for exploitation. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

Upgrading to version 4.89.0 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• fleetdm

Name

• Fleet

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14
• 4.15
• 4.16
• 4.17
• 4.18
• 4.19
• 4.20
• 4.21
• 4.22
• 4.23
• 4.24
• 4.25
• 4.26
• 4.27
• 4.28
• 4.29
• 4.30
• 4.31
• 4.32
• 4.33
• 4.34
• 4.35
• 4.36
• 4.37
• 4.38
• 4.39
• 4.40
• 4.41
• 4.42
• 4.43
• 4.44
• 4.45
• 4.46
• 4.47
• 4.48
• 4.49
• 4.50
• 4.51
• 4.52
• 4.53
• 4.54
• 4.55
• 4.56
• 4.57
• 4.58
• 4.59
• 4.60
• 4.61
• 4.62
• 4.63
• 4.64
• 4.65
• 4.66
• 4.67
• 4.68
• 4.69
• 4.70
• 4.71
• 4.72
• 4.73
• 4.74
• 4.75
• 4.76
• 4.77
• 4.78
• 4.79
• 4.80
• 4.81
• 4.82
• 4.83
• 4.84
• 4.85
• 4.86
• 4.87
• 4.88

Website

• Product: https://github.com/fleetdm/fleet/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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