Icinga 2 up to 2.14.8/2.15.3/2.16.1 JSON Parser stack-based overflow

Summaryinfo

A vulnerability marked as very critical has been reported in Icinga 2 up to 2.14.8/2.15.3/2.16.1. The affected element is an unknown function of the component JSON Parser. This manipulation causes stack-based overflow. This vulnerability is tracked as CVE-2026-61551. The attack is possible to be carried out remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Icinga 2 up to 2.14.8/2.15.3/2.16.1 and classified as very critical. Affected by this vulnerability is an unknown code of the component JSON Parser. The manipulation with an unknown input leads to a stack-based overflow vulnerability. The CWE definition for the vulnerability is CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-61551 since 07/10/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/18/2026).

Upgrading to version 2.14.9, 2.15.4 or 2.16.2 eliminates this vulnerability.

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Productinfo

Vendor

• Icinga

Name

• 2

Version

• 2.14.0
• 2.14.1
• 2.14.2
• 2.14.3
• 2.14.4
• 2.14.5
• 2.14.6
• 2.14.7
• 2.14.8
• 2.15.0
• 2.15.1
• 2.15.2
• 2.15.3
• 2.16.0
• 2.16.1

CPE 2.3info

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CPE 2.2info

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