# CVE-2025-42611: Improper certificate validation in multiple RouterOS services

> Attackers can bypass authentication in RouterOS services like OpenVPN and CAPsMAN by exploiting improper certificate validation logic.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A: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 May 2026
- **Updated:** 5 May 2026
- **Also known as:** GHSA-qqqc-gw7p-pw85

## What is CVE-2025-42611?

CVE-2025-42611 is a medium-severity authentication bypass vulnerability in Mikrotik RouterOS, published on 5 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

RouterOS provides various services that rely on correct
verification of client and server certificates to secure confidentiality and
integrity of communications. This includes OpenVPN, CAPsMAN, Dot1x (802.1X),
among others.

The vulnerability lies in shared certificate validation
logic which uses the system certificate store that is shared and equally
trusted by all system services. This causes confusion of scope, allowing any
certificate authority present in the system-wide trust store to be trusted in
any context (with some exceptions), allowing partial or full authentication
bypass in CAPsMAN, OpenVPN, Dot1X and potentially others.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2025-42611?


## How do I fix CVE-2025-42611?

No fix has been published for CVE-2025-42611 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-42611 being exploited?

There is no known exploitation of CVE-2025-42611 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-42611 and fix it if it is affected.

What it is: CVE-2025-42611 is a medium-severity authentication bypass vulnerability in Mikrotik RouterOS, published on 5 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-2025-42611 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-2025-42611/ (Markdown: https://insights.sbomify.com/CVE-2025-42611/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-42611
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-42611
- OSV: https://osv.dev/vulnerability/CVE-2025-42611

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-42611/
Summaries are generated and may contain mistakes; the official description above is the record.