---
id: CVE-2026-61551
title: Icinga 2 is an open source monitoring system
summary: >-
  Icinga 2 is an open source monitoring system. Prior to 2.14.9, 2.15.4, and
  2.16.2, parsing deeply nested JSON can exhaust the call stack because nesting
  depth is not bounded. The affected JSON parsing paths are reachable by
  unauthenticat…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H'
cwe:
  - CWE-674
vendor: Icinga
product: icinga2
affected:
  - icinga2 < 2.14.9
  - 'icinga2 >= 2.15.0, < 2.15.4'
  - 'icinga2 >= 2.16.0, < 2.16.2'
published: '2026-09-18'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T21:17:43.237'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-61551'
references:
  - url: >-
      https://github.com/Icinga/icinga2/commit/391504eaa9ed9aee81f84008c57ec821974b74ee
    label: security-advisories@github.com
  - url: >-
      https://github.com/Icinga/icinga2/commit/3d9166ff52ff1a64a286c39af57957d63442c137
    label: security-advisories@github.com
  - url: >-
      https://github.com/Icinga/icinga2/commit/4964d2444ca5c4fae9036054554e1c6e0025fb89
    label: security-advisories@github.com
  - url: >-
      https://github.com/Icinga/icinga2/commit/ed163a8aa9d296820dd2ad14c47bf3f6a3fcce7d
    label: security-advisories@github.com
  - url: 'https://github.com/Icinga/icinga2/pull/10908'
    label: security-advisories@github.com
  - url: 'https://github.com/Icinga/icinga2/releases/tag/v2.14.9'
    label: security-advisories@github.com
  - url: 'https://github.com/Icinga/icinga2/releases/tag/v2.15.4'
    label: security-advisories@github.com
  - url: 'https://github.com/Icinga/icinga2/releases/tag/v2.16.2'
    label: security-advisories@github.com
  - url: 'https://github.com/Icinga/icinga2/security/advisories/GHSA-wh38-wg57-5w7g'
    label: security-advisories@github.com
  - url: 'https://icinga.com/blog/icinga2-security-release-v2-16-2'
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-24T21:01:25.297652Z'
epss: 0.00941
epssPercentile: 0.59254
ingestedAt: '2026-09-18T17:46:41.543Z'
---

## Overview

Icinga 2 is an open source monitoring system. Prior to 2.14.9, 2.15.4, and 2.16.2, parsing deeply nested JSON can exhaust the call stack because nesting depth is not bounded. The affected JSON parsing paths are reachable by unauthenticated network clients through the Icinga 2 service on TCP port 5665, allowing a remote attacker to crash the process, while possible code execution has not been demonstrated. This issue is fixed in versions 2.14.9, 2.15.4, and 2.16.2.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.