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.
CVE-2026-61551
HIGHPre-NVD 8.68.6
EchelonGraph scoreLOW confidence
This high-severity CVE scores 8.6 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: secondary
8.6EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.6Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.6
- EG Score
- 8.6(low)
- EG Risk
- 43(Track)EG Risk 43/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity86% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 1%
- EPSS %ILE
- 43%
- KEV
- Not listed
Published
September 18, 2026
Last Modified
September 18, 2026
Advisory Details (10)
Auto-updated Sep 18, 2026Patch available. Sources: github_release, github, github_pr, github_commit.
generic
Releasing Icinga 2 v2.16.2, 2.15.4 and 2.14.9
https://icinga.com/blog/icinga2-security-release-v2-16-2github_release Patch Available
Icinga 2 v2.16.2
Patch available: Icinga/icinga2 v2.16.2
https://github.com/Icinga/icinga2/releases/tag/v2.16.2github_release Patch Available
Icinga 2 v2.15.4
Patch available: Icinga/icinga2 v2.15.4
https://github.com/Icinga/icinga2/releases/tag/v2.15.4github_release Patch Available
Icinga 2 v2.14.9
Patch available: Icinga/icinga2 v2.14.9
https://github.com/Icinga/icinga2/releases/tag/v2.14.9github_commit Patch Available
commit ed163a8aa9d2 (Icinga/icinga2)
Patch available: Icinga/icinga2 v2.16.2 (contains commit ed163a8aa9d2)
https://github.com/Icinga/icinga2/commit/ed163a8aa9d296820dd2ad14c47bf3f6a3fcce7dgithub_commit
commit 4964d2444ca5 (Icinga/icinga2)
Fix landed in Icinga/icinga2 commit 4964d2444ca5 — awaiting tagged release
https://github.com/Icinga/icinga2/commit/4964d2444ca5c4fae9036054554e1c6e0025fb89github_commit Patch Available
commit 3d9166ff52ff (Icinga/icinga2)
Patch available: Icinga/icinga2 v2.15.4 (contains commit 3d9166ff52ff)
https://github.com/Icinga/icinga2/commit/3d9166ff52ff1a64a286c39af57957d63442c137github_commit Patch Available
commit 391504eaa9ed (Icinga/icinga2)
Patch available: Icinga/icinga2 v2.14.9 (contains commit 391504eaa9ed)
https://github.com/Icinga/icinga2/commit/391504eaa9ed9aee81f84008c57ec821974b74eegithub_pr
[GHSA-wh38-wg57-5w7g] Fix stack overflow due to deeply nested data structures
Fix merged in Icinga/icinga2 PR #10908 on 2026-06-29 — awaiting tagged release
https://github.com/Icinga/icinga2/pull/10908github Patch Available
Stack overflow via deeply nested JSON objects · Advisory · Icinga/icinga2 · GitHub
https://github.com/Icinga/icinga2/security/advisories/GHSA-wh38-wg57-5w7gWeakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 3× in last 7d / 3× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-09-18 18:27 UTCEG score recompute
- 2026-09-18 17:29 UTCEG score recompute
- 2026-09-18 17:29 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-61551?
CVE-2026-61551 is a high vulnerability published on September 18, 2026. 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…
When was CVE-2026-61551 disclosed?
CVE-2026-61551 was first published in the National Vulnerability Database on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-61551 actively exploited?
CVE-2026-61551 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 57.5% of all scored CVEs.
What is the CVSS score of CVE-2026-61551?
CVE-2026-61551 has a CVSS v3 base score of 8.6 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-61551?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-61551, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-61551
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