Denial of Service Vulnerability in Fleet by FleetDM

CVE-2026-111924

What is CVE-2026-111924?

Fleet versions prior to 4.83.0 are susceptible to a denial of service vulnerability that allows unauthenticated attackers to exploit gzip-compressed request bodies. By sending small requests with a Content-Encoding: gzip header to unauthenticated endpoints, attackers can trigger excessive memory consumption during request decoding. This can lead to crashing the entire Fleet instance, disrupting services and potentially causing significant downtime for users. Proper mitigation strategies are essential to protect against this vulnerability.

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