Vulnerability in Fleet Device Management Software by FleetDM
CVE-2026-46356

6.9MEDIUM

Key Information:

Vendor

Fleetdm

Status
Fleet
Vendor
CVE Published:
14 May 2026

What is CVE-2026-46356?

Fleet, an open-source device management platform, has a vulnerability in its IP extraction mechanism that enables unauthenticated attackers to bypass API rate limiting. This occurs due to the software's failure to validate the origins of client IP headers like True-Client-IP, X-Real-IP, and X-Forwarded-For. As a result, malicious actors can spoof these headers, making Fleet's system perceive multiple requests as coming from distinct clients. Consequently, this oversight can lead to unrestricted brute-force login attempts against publicly exposed Fleet instances. It is crucial for users to upgrade to version 4.80.1, which addresses this issue, or ensure their deployments are secured behind reliable reverse proxies, such as nginx or AWS ALB, that appropriately manage IP header overwrites.

Affected Version(s)

fleet < 4.80.1

References

https://github.com/fleetdm/fleet/security/advisories/GHSA...
x_refsource_CONFIRM
https://github.com/fleetdm/fleet/releases/tag/fleet-v4.80.1
x_refsource_MISC

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.