CVE-2025-26466 PoC — Openssh: denial-of-service in openssh

Source

https://github.com/mrowkoob/CVE-2025-26466-msf

Associated Vulnerability

Title: Openssh: denial-of-service in openssh (CVE-2025-26466)
Description:A flaw was found in the OpenSSH package. For each ping packet the SSH server receives, a pong packet is allocated in a memory buffer and stored in a queue of packages. It is only freed when the server/client key exchange has finished. A malicious client may keep sending such packages, leading to an uncontrolled increase in memory consumption on the server side. Consequently, the server may become unavailable, resulting in a denial of service attack.

Description

CVE-2025-26466 - SSH Ping DoS Ruby module for Metasploit Framework

Readme

# CVE-2025-26466 (Metasploit module)

OpenSSH (versions 9.5p1 to 9.9p1) is vulnerable to a memory and CPU exhaustion DoS Attack by sending repeated SSH2_MSG_PING packets (type 192). 
This occurs before authentication, and can result in server lockup due to poor queue/buffer handling.

## More information about that CVE:
```
https://nvd.nist.gov/vuln/detail/CVE-2025-26466
```

 ## How do I run this script?

Copy .rb file into your 'modules' folder, f.e.

`/usr/share/metasploit-framework/modules/auxiliary/dos/ssh`

Run Metasploit console and search for the module.

```
msfconsole
search ping_dos
```

## References

- https://blog.qualys.com/vulnerabilities-threat-research/2025/02/18/qualys-tru-discovers-two-vulnerabilities-in-openssh-cve-2025-26465-cve-2025-26466


## Disclaimer

I am sharing this just for educational purposes, you shall not use it on infrastructure you are not authorized to.

## Issues

That's my first project shared on GitHub. Feel free to leave comments about it, so I can learn and make it better.

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