Fleet's unbounded request body read allows remote Denial of Service in github.com/fleetdm/fleet

Open Source Vulnerabilities GHSA-99hj-44vg-hfcp

### Summary 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. ### Impact An unauthenticated attacker could cause the Fleet server process to exhaust available memory and restart by sending oversized or repeated HTTP requests to affected endpoints. This vulnerability impacts **availability only**. There is: - No exposure of sensitive data - No authentication bypass - No privilege escalation - No integrity impact ### Workarounds If upgrading immediately is not possible, the following mitigations can reduce exposure: - Apply request body size limits at a reverse proxy or load balancer (e.g., NGINX, Envoy). - Restrict network access to endpoints to known IP ranges where feasible. - Monitor memory usage and restart frequency for abnormal patterns. ### For More Information If there are any questions or concerns about this advisory, please contact us at: Email Fleet at [[email protected]](mailto:[email protected]) ### Credits Fleet thanks @fuzzztf for responsibly reporting this issue.

Open Source Vulnerabilities GO-2026-4889

Fleet's unbounded request body read allows remote Denial of Service in github.com/fleetdm/fleet. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. (If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.) The additional affected modules and versions are: github.com/fleetdm/fleet/v4 before v4.43.5-0.20260113202849-bbc1aef2987d.

Open Source Vulnerabilities CVE-2026-26061

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.