---
cve: "CVE-2026-77021"
severity: "MEDIUM"
cvss: 5.3
epss: "5.1%"
vendor: "Checkmk GmbH"
kev: false
exploited: false
published: "2026-09-21 11:17:12"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-22T01:44:47+02:00"
---

# CVE-2026-77021

> 5.3 MEDIUM

## Beschreibung

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.

## CVSS-Vektor

```
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
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |

## Referenzen

- <https://checkmk.com/werk/22116>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-77021) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_