# CVE-2024-27686: Denial of service in n/a

> Remote attackers can crash Mikrotik RouterOS devices by sending crafted packets to the SMB service, requiring an upgrade to version 7.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 8 May 2026
- **Updated:** 8 May 2026
- **Also known as:** GHSA-rx53-rx95-fqqm

## What is CVE-2024-27686?

CVE-2024-27686 is a high-severity denial of service vulnerability in n/a, published on 8 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Mikrotik RouterOS (x86) 6.40.5 through 6.49.10 (fixed in 7) allows a remote attacker to cause a denial of service (device crash) via crafted packet data to the SMB service on TCP port 445.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2024-27686?


## How do I fix CVE-2024-27686?

No fix has been published for CVE-2024-27686 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-27686 being exploited?

There is no known exploitation of CVE-2024-27686 in the wild and no public exploit code.

Public exploit code:

- This document describes a Denial of Service (DoS) vulnerability found in certain versions of MikroTik RouterOS. The vulnerability is due to insufficient handling of crafted SMB requests. A remote attacker could exploit this issue by sending a specially crafted request to the target server. (github_poc): https://github.com/ThemeHackers/CVE-2024-27686

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-27686 and fix it if it is affected.

What it is: CVE-2024-27686 is a high-severity denial of service vulnerability in n/a, published on 8 May 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-2024-27686 in the wild and no public exploit code.

Affected product: n/a. 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-2024-27686/ (Markdown: https://insights.sbomify.com/CVE-2024-27686/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-27686
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-27686
- OSV: https://osv.dev/vulnerability/CVE-2024-27686

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-27686/
Summaries are generated and may contain mistakes; the official description above is the record.