8.6
HIGH CVSS 3.1
CVE-2026-61551
Icinga 2: Stack overflow via deeply nested JSON objects
Description

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.

INFO

Published Date :

Sept. 18, 2026, 6:17 p.m.

Last Modified :

Sept. 18, 2026, 6:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-61551 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH [email protected]
Solution
Update Icinga 2 to a patched version to prevent stack exhaustion via nested JSON parsing.
  • Update Icinga 2 to version 2.14.9 or later.
  • Update Icinga 2 to version 2.15.4 or later.
  • Update Icinga 2 to version 2.16.2 or later.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-61551 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-61551 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-61551 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-61551 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Sep. 18, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
    Added CWE CWE-674
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/61xxx/CVE-2026-61551.json">CVE-2026-61551</a>
    Added Reference https://github.com/Icinga/icinga2/commit/391504eaa9ed9aee81f84008c57ec821974b74ee
    Added Reference https://github.com/Icinga/icinga2/commit/3d9166ff52ff1a64a286c39af57957d63442c137
    Added Reference https://github.com/Icinga/icinga2/commit/4964d2444ca5c4fae9036054554e1c6e0025fb89
    Added Reference https://github.com/Icinga/icinga2/commit/ed163a8aa9d296820dd2ad14c47bf3f6a3fcce7d
    Added Reference https://github.com/Icinga/icinga2/pull/10908
    Added Reference https://github.com/Icinga/icinga2/releases/tag/v2.14.9
    Added Reference https://github.com/Icinga/icinga2/releases/tag/v2.15.4
    Added Reference https://github.com/Icinga/icinga2/releases/tag/v2.16.2
    Added Reference https://github.com/Icinga/icinga2/security/advisories/GHSA-wh38-wg57-5w7g
    Added Reference https://icinga.com/blog/icinga2-security-release-v2-16-2
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.