Icinga 2: Stack overflow via deeply nested JSON objects
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- Low · Low · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-674.
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 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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Icinga | icinga2 | before 2.14.9; 2.15.0 to before 2.15.4; 2.16.0 to before 2.16.2 | 2.14.9, 2.15.4, 2.16.2 | Patch available | CNA |
- icinga2 VendorIcinga Affected before 2.14.9; 2.15.0 to before 2.15.4; 2.16.0 to before 2.16.2 Fixed in 2.14.9, 2.15.4, 2.16.2 Patch available CNA
Remediation
- Fix · CNA icinga2 (Icinga) Fixed in 2.14.9, 2.15.4, 2.16.2
Timeline
- 2026-10-02 Threatist record created from CVE-2026-61551
References
Other 10
- https://github.com/Icinga/icinga2/security/advisories/GHSA-wh38-wg57-5w7g
- https://github.com/Icinga/icinga2/pull/10908
- 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/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://icinga.com/blog/icinga2-security-release-v2-16-2
More Icinga vulnerabilities
- TI-2022-08531 Path traversal in Icinga Web 2 CVSS 3.1HIGH 7.5
- TI-2024-16337 Icinga Director configuration is susceptible to Cross-Site Request Forgery CVSS 3.1HIGH 8.3
- TI-2012-05060 Multiple stack-based buffer overflows in the get_history function in history.cgi in… CVSS 2.0HIGH 7.5
- TI-2013-05840 Multiple off-by-one errors in Nagios Core 3.5.1, 4.0.2, and earlier, and Icinga before… CVSS 2.0MEDIUM 5.5
- TI-2022-08530 Arbitrary code execution for authenticated users in Icinga Web 2 CVSS 3.1HIGH 8.8
- TI-2024-32957 Icinga 2 has a TLS Certificate Validation Bypass for JSON-RPC and HTTP API Connections CVSS 3.1CRITICAL 9.8
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences