Vulnerability · Published Mar 27, 2026 · Assigned by GitHub_M

CVE-2026-26061Fleet's unbounded request body read allows remote Denial of Service

High 8.7

In plain English

A high-severity resource allocation without limits in fleet from fleetdm. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.7High

Exploit odds (30 days)0.5%top 60.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Fleet is open source device management software. Prior to 4.81.0, Fleet contained multiple unauthenticated HTTP endpoints that read request bodies without enforcing a size limit. An unauthenticated attacker could exploit this behavior by sending large or repeated HTTP payloads, causing excessive memory allocation and resulting in a denial-of-service (DoS) condition. Version 4.81.0 patches the issue.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/fleetdm/fleet/v4	4.43.5-0.20260113202849-bbc1aef2987d	GHSA-99hj-44vg-hfcp
Go	github.com/fleetdm/fleet/v4	no fix listed	GO-2026-4889

Affected products (as reported)

Vendor	Product	Versions
fleetdm	fleet	< 4.81.0

Weakness: CWE-770 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References

https://github.com/fleetdm/fleet/security/advisories/GHSA-99hj-44vg-hfcp x_refsource_CONFIRM