Icinga 2 is widely used for enterprise monitoring; unauthenticated remote compromise of nodes can disrupt monitoring and trust across organizations.
CVE-2026-61550
Unauthenticated attacker can replace certs and fully compromise Icinga 2 nodes via TCP/5665.
Is CVE-2026-61550 being exploited?
Not confirmed. CVE-2026-61550 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked.
How severe is CVE-2026-61550?
CVE-2026-61550 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-61550?
Yes. A fix has been recorded for CVE-2026-61550. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-61550 affect?
CVE-2026-61550 affects Icinga 2 v2.8 through prior-to-2.14.9, Icinga 2 v2.15.0-2.15.3, Icinga 2 v2.16.0-2.16.1. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-61550?
Upgrade to 2.14.9, 2.15.4 or 2.16.2 and restrict access to TCP/5665
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated network attacker connecting to TCP/5665 can replace node and CA certificates, impersonate trusted nodes, and take full control of the node.
Immediate action required
- affected>= 2.8 and < 2.14.9
- affected>= 2.15.0 and < 2.15.4
- affected>= 2.16.0 and < 2.16.2
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.