CVE-2026-34389: GO-2026-4912 - Fleet's user account creation via invite does not enforce invited email address in github.com/fleetdm/fleet

CVE-2026-34389 · Severity: medium · CVSS 6.5 · Published 2026-03-27

Fleet is open source device management software. Prior to 4.81.0, Fleet contained an issue in the user invitation flow where the email address provided during invite acceptance was not validated against the email address associated with the invite. An attacker who obtained a valid invite token could create an account under an arbitrary email address while inheriting the role granted by the invite, including global admin. Version 4.81.0 patches the issue.

Technologies: Fleetdm Fleet, github.com/fleetdm/fleet/v4 (Go). Vendors: Fleetdm, Go.

Quick answers

Is CVE-2026-34389 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-34389 being exploited in the wild.
How severe is CVE-2026-34389?
Medium severity, with a CVSS score of 6.5, published 27 March 2026.
Which products and versions are affected?
github.com/fleetdm/fleet/v4 (Go) SEMVER:introduced=0,fixed=4.81.0.
Is there a fix for CVE-2026-34389?
Yes. github.com/fleetdm/fleet/v4 (Go): upgrade to 4.81.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-34389?
Check whether you run Fleetdm Fleet or github.com/fleetdm/fleet/v4 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/fleetdm/fleet/v4 (Go): upgrade to 4.81.0 or later
    go get github.com/fleetdm/fleet/v4@v4.81.0

Affected products

  • Fleetdm Fleet
  • github.com/fleetdm/fleet/v4 (Go) SEMVER:introduced=0,fixed=4.81.0

Identifiers

  • CVE-2026-34389
  • GHSA-4f9r-x588-pp2h
  • GO-2026-4912

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