8.6

CVE-2026-61551: icinga icinga2 Uncontrolled Recursion

CVSS: 8.6v3.1HighAwaiting analysis
AliasesUBUNTU-CVE-2026-61551DEBIAN-CVE-2026-61551
Published 18-09-2026Last modified 24-09-2026
Open JSON

Vulnerability summary

CVE-2026-61551 is a high (CVSS 8.6) Uncontrolled Recursion vulnerability in icinga icinga2. EPSS estimates a 0.94% chance of exploitation in the next 30 days, higher than 60.3% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.6/10
010
High · v3.1 (CVE.org)
EPSS score
0.94%
0%100%
Low · +0.43 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 18-09-2026
    PublishedVulnerability first disclosed.
  2. 24-09-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.94%

Chance of exploitation in the next 30 days

Percentile

60%

Versus all other CVEs

30-day change

+0.43 pp

From 0.51% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.94%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • icinga2All versions (No fix recorded) | < 2.14.6-1+deb13u1 | < 2.16.2-1
Icinga1 product
  • icinga2< 2.14.9 | ≥ 2.15.0, < 2.15.4 | ≥ 2.16.0, < 2.16.2
Ubuntu1 product
  • icinga2All versions (No fix recorded)

3 vendors · 3 products

References

14 links
Show all 14 references