CVE-2026-23999: fleetdm fleet Use of Insufficiently Random Values

Vulnerability summary

CVE-2026-23999 is a medium (CVSS 5.5) Use of Insufficiently Random Values vulnerability in fleetdm fleet. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2.2% of scored vulnerabilities.

Timeline

1. 26-02-2026
   PublishedVulnerability first disclosed.
2. 26-02-2026
   Last modifiedVulnerability information updated.

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.

• CWE-330Use of Insufficiently Random ValuesThe product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.