# CVE-2026-67276: SSH user impersonation possible in Mikrotik RouterOS

> Attackers can impersonate SSH users by forging signatures using a modified RSA key, bypassing authentication to execute commands as the target user.

- **Severity:** Critical 9.2 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Sep 2026
- **Updated:** 9 Sep 2026
- **Also known as:** GHSA-j9wg-77fw-f22f

## What is CVE-2026-67276?

CVE-2026-67276 is a critical authentication bypass vulnerability in Mikrotik Routeros, published on 5 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

RouterOS does not compare the complete RSA public key when matching an SSH authentication request to an authorized user key, checking the key type and modulus but omitting the exponent. Because signature verification uses the client-supplied key, an attacker knowing an authorized RSA modulus can supply a key with exponent one, forge a valid signature, and open an SSH command channel as the target user without the private key.This issue affects only 7.x branch was fixed in versions: 7.23.4 (Long-term) and 7.24.2 (Stable)

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2026-67276?

It affects 1 product.


Products: Mikrotik Routeros.

## How do I fix CVE-2026-67276?

No fix has been published for CVE-2026-67276 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-67276 being exploited?

There is no known exploitation of CVE-2026-67276 in the wild and no public exploit code.

Public exploit code:

- CVE-2026-67276 RouterOS SSH public-key authentication bypass lab PoC (github_poc): https://github.com/dinosn/mikrotrick-poc
- CVE-2026-67276 MikroTik RouterOS SSH Authentication Bypass Exploit (github_poc): https://github.com/BlackHatExploitation/exploit-mikrotik-2026
- Testing tool for the Mikrotrick exploit (CVE-2026-67276) (github_poc): https://github.com/4rt-Net/Mikrotrick_POC
- CVE-2026-67276 - Draft or TODO (github_poc): https://github.com/HORKimhab/CVE-2026-67276

## Other vulnerabilities in Mikrotik Routeros

- [CVE-2018-7445](https://insights.sbomify.com/CVE-2018-7445/): MikroTik RouterOS Stack-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2026-86060](https://insights.sbomify.com/CVE-2026-86060/): MikroTik RouterOS Improper Neutralization of Argument Delimiters in a Command (critical 9.2, exploited in the wild)
- [CVE-2018-14847](https://insights.sbomify.com/CVE-2018-14847/): MikroTik Router OS Directory Traversal (critical 9.1, exploited in the wild)
- [CVE-2026-67277](https://insights.sbomify.com/CVE-2026-67277/): MikroTik RouterOS Missing Authentication for Critical Function (high 8.8, exploited in the wild)
- [CVE-2026-67279](https://insights.sbomify.com/CVE-2026-67279/): Mikrotik RouterOS Improper Enforcement of Behavioral Workflow (medium 6.9, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-67276 and fix it if it is affected.

What it is: CVE-2026-67276 is a critical authentication bypass vulnerability in Mikrotik Routeros, published on 5 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-2026-67276 in the wild and no public exploit code.

Affected product: Mikrotik Routeros. 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-2026-67276/ (Markdown: https://insights.sbomify.com/CVE-2026-67276/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-67276
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-67276
- OSV: https://osv.dev/vulnerability/CVE-2026-67276

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-67276/
Summaries are generated and may contain mistakes; the official description above is the record.