Auth bypass in Fleetdm Fleet

CVE-2026-25963

Fleet is open source device management software. In versions prior to 4.80.1, a broken authorization check in Fleet’s certificate template deletion API could allow a team administrator to delete certificate templates belonging to other teams within the same Fleet instance. Fleet supports certificate templates that are scoped to individual teams. In affected versions, the batch deletion endpoint validated authorization using a user-supplied team identifier but did not verify that the certificate template IDs being deleted actually belonged to that team. As a result, a team administrator could delete certificate templates associated with other teams, potentially disrupting certificate-based workflows such as device enrollment, Wi-Fi authentication, VPN access, or other certificate-dependent configurations for the affected teams. This issue does not allow privilege escalation, access to sensitive data, or compromise of Fleet’s control plane. Impact is limited to integrity and availability of certificate templates across teams. Version 4.80.1 patches the issue. If an immediate upgrade is not possible, administrators should restrict access to certificate template management to trusted users and avoid delegating team administrator permissions where not strictly required.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.003 (25.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 25.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-25963: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-25963?
CVE-2026-25963 is a medium-severity vulnerability in Fleetdm Fleet, classified under Incorrect Authorization. CVSS score: 6.5/10. Published 2026-02-26.
How severe is CVE-2026-25963?
Medium severity. CVSS v3 base score is 6.5 out of 10.