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OpenAdvisories
Medium · 5.3 CVE-2026-77021 EUVD-2026-83883GHSA-5q8h-fhcg-2395

Missing decompression size limit in agent receiver allows memory exhaustion via push agent data

Published Sep 21, 2026 · Updated Sep 21, 2026 · Assigned by Checkmk

Description

Improper handling of highly compressed data (data amplification) in Checkmk <2.5.0p14, <2.4.0p37, <2.3.0p51 and 2.2.0 (EOL) allows an attacker who controls a host registered for push mode to exhaust the memory of the agent receiver by sending a small zlib compressed payload that decompresses to an arbitrary size.

Affected products

VendorProductAffectedFixed
Checkmk Checkmk 2.5.0 – < 2.5.0p14, 2.4.0 – < 2.4.0p37, 2.3.0 – < 2.3.0p51, 2.2.0 2.5.0p14

Advisories 1

References