Fleet: Device lock PIN can be predicted if lock time is known

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

4.1 · CVSS:4.0/AV:P/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-23999: 0.14% estimated exploitation activity in the next 30 days; percentile 3.43 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Fleet generated device lock and wipe PINs using a predictable algorithm based solely on the current Unix timestamp. Because no secret key or additional entropy was used, the resulting PIN could potentially be derived if the approximate time the device was locked is known. Impact Fleet’s device lock and wipe commands generate a 6-digit PIN that is displayed to administrators for unlocking a device. In affected versions, this PIN was deterministically derived from the current timestamp. An attacker with physical possession of a locked device and knowledge of the approximate time the lock command was issued could theoretically predict the correct PIN within a limited search window. However, successful exploitation is constrained by multiple factors: - Physical access to the device is required. - The approximate lock time must be known. - The operating system enforces rate limiting on PIN entry attempts. - Attempts would need to be spread over multiple days. - Device wipe…

Published by the source

26 Feb 2026, 19:35 UTC

Last modified by the source

10 Mar 2026, 18:22 UTC

Source last checked

26 Oct 2026, 15:15 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-ppwx-5jq7-px2w

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# Patch Next advisory brief: CVE-2026-23999

Advisory: Fleet: Device lock PIN can be predicted if lock time is known
IDs: CVE-2026-23999, GHSA-ppwx-5jq7-px2w
Record: https://patchnext.com/advisories/cve-2026-23999 (revision 1, source checked 26 Oct 2026, 15:15 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/fleetdm/fleet/v4 4.80.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/fleetdm/fleet/v4: affected < 4.80.1; fixed in 4.80.1

## Suggested inspection (read-only)
- Go github.com/fleetdm/fleet/v4: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/fleetdm/fleet/v4.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-ppwx-5jq7-px2w (GitHub-reviewed advisory GHSA-ppwx-5jq7-px2w lists affected ranges: Go github.com/fleetdm/fleet/v4 >=0 <4.80.1)

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