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

> Unauthenticated attackers can replace node certificates via JSON-RPC, impersonate trusted nodes, and take control of the monitoring system.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Sep 2026
- **Updated:** 21 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-61550, GHSA-vj39-ww8j-vvx5, UBUNTU-CVE-2026-61550

## What is CVE-2026-61550?

CVE-2026-61550 is a critical missing authorization vulnerability in icinga2, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-61550?


## How do I fix CVE-2026-61550?

Upgrade to a fixed version.

## Is CVE-2026-61550 being exploited?

There is no known exploitation of CVE-2026-61550 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-61550 and fix it if it is affected.

What it is: CVE-2026-61550 is a critical missing authorization vulnerability in icinga2, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-61550 in the wild and no public exploit code.

Affected product: icinga2. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-61550/ (Markdown: https://insights.sbomify.com/CVE-2026-61550/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-61550
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-61550
- OSV: https://osv.dev/vulnerability/CVE-2026-61550

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-61550/
Summaries are generated and may contain mistakes; the official description above is the record.