# CVE-2026-27849: Missing neutralization in Linksys MR9600, Linksys MX4200

> Attackers can inject OS commands via TLS-SRP update functionality in Linksys mesh routers, leading to remote code execution.

- **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:** No
- **Published:** 25 Feb 2026
- **Updated:** 26 Feb 2026
- **Also known as:** GHSA-f2jw-4mh9-f63v

## What is CVE-2026-27849?

CVE-2026-27849 is a critical command injection vulnerability in Linksys MR9600, published on 25 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Due to missing neutralization of special elements, OS commands can be injected via the update functionality of a TLS-SRP connection, which is normally used for configuring devices inside the mesh network.
This issue affects MR9600: 1.0.4.205530; MX4200: 1.0.13.210200.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-27849?


## How do I fix CVE-2026-27849?

No fix has been published for CVE-2026-27849 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-27849 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-27849 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-27849 and fix it if it is affected.

What it is: CVE-2026-27849 is a critical command injection vulnerability in Linksys MR9600, published on 25 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-27849 exists.

Affected product: Linksys MR9600. 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-2026-27849/ (Markdown: https://insights.sbomify.com/CVE-2026-27849/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-27849
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-27849
- OSV: https://osv.dev/vulnerability/CVE-2026-27849

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-27849/
Summaries are generated and may contain mistakes; the official description above is the record.