8.6High
CVE-2026-61551
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.
What this means for your business
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
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Scoring
- CVSS
- 8.6 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H- Weakness
- CWE-674
- Assigned by
- security-advisories@github.com
Dates
- Published
- 2026-09-18
- Last modified
- 2026-09-24
- Sources
- NVD
References
- https://github.com/Icinga/icinga2/commit/391504eaa9ed9aee81f84008c57ec821974b74ee
- https://github.com/Icinga/icinga2/commit/3d9166ff52ff1a64a286c39af57957d63442c137
- https://github.com/Icinga/icinga2/commit/4964d2444ca5c4fae9036054554e1c6e0025fb89
- https://github.com/Icinga/icinga2/commit/ed163a8aa9d296820dd2ad14c47bf3f6a3fcce7d
- https://github.com/Icinga/icinga2/pull/10908
- https://github.com/Icinga/icinga2/releases/tag/v2.14.9
- https://github.com/Icinga/icinga2/releases/tag/v2.15.4
- https://github.com/Icinga/icinga2/releases/tag/v2.16.2
- https://github.com/Icinga/icinga2/security/advisories/GHSA-wh38-wg57-5w7g
- https://icinga.com/blog/icinga2-security-release-v2-16-2