# CVE-2026-86427: LibreNMS before 26.8.0 Argument Injection via graph_title

> Authenticated attackers can inject arguments into rrdtool to execute arbitrary commands or read unauthorized RRD files in LibreNMS.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Sep 2026
- **Updated:** 10 Sep 2026
- **Also known as:** GHSA-3hvv-wxpw-cx83, GHSA-j7jc-m6xg-rrcw

## What is CVE-2026-86427?

CVE-2026-86427 is a high-severity command injection vulnerability in Librenms Librenms, published on 7 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

LibreNMS before 26.8.0 contains an argument injection vulnerability in the graph_title parameter that allows authenticated attackers to inject arbitrary rrdtool arguments by breaking out of double-quote escaping. Attackers can inject DEF and LINE arguments to read RRD files from unauthorized devices, or use newline injection to execute arbitrary rrdtool commands, bypassing per-device authorization checks.

Weakness: CWE-77 (Improper Neutralization of Special Elements used in a Command)

## Which versions are affected by CVE-2026-86427?

It affects 1 product.


Products: Librenms Librenms.

## How do I fix CVE-2026-86427?

No fix has been published for CVE-2026-86427 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-86427 being exploited?

There is no known exploitation of CVE-2026-86427 in the wild and no public exploit code.

## Other vulnerabilities in Librenms Librenms

- [CVE-2023-4982](https://insights.sbomify.com/CVE-2023-4982/): Cross-site Scripting (XSS) - Stored in librenms/librenms (critical 9.8)
- [CVE-2022-29712](https://insights.sbomify.com/CVE-2022-29712/): Command injection in librenms (critical 9.8)
- [CVE-2021-44278](https://insights.sbomify.com/CVE-2021-44278/): Path traversal in librenms/librenms (critical 9.8)
- [CVE-2019-10665](https://insights.sbomify.com/CVE-2019-10665/): LibreNMS Information Disclosure (critical 9.8)
- [CVE-2018-20434](https://insights.sbomify.com/CVE-2018-20434/): LibreNMS arbitrary OS commands execution (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-86427 and fix it if it is affected.

What it is: CVE-2026-86427 is a high-severity command injection vulnerability in Librenms Librenms, published on 7 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-86427 in the wild and no public exploit code.

Affected product: Librenms Librenms. 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-2026-86427/ (Markdown: https://insights.sbomify.com/CVE-2026-86427/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-86427
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-86427
- OSV: https://osv.dev/vulnerability/CVE-2026-86427

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-86427/
Summaries are generated and may contain mistakes; the official description above is the record.