CVE-2026-77021

5.3 mediumEPSS 0.4%

Medium (5.3). EPSS 0.4% chance of exploitation in the next 30 days.

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.

Severity

CVSS 4.0

5.3 medium

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

EPSS: 0.4% chance of exploitation in the next 30 days; higher than 32% of CVEs (scores of 2026-10-31)
CWE: CWE-409
Published: 2026-09-21
Modified: 2026-09-21
Record from: the NVD, synced 2026-10-19

References

https://checkmk.com/werk/22116

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