CVE-2025-3091 MB connect line: Authorization bypass in mbCONNECT24/mymbCONNECT24
An attacker with another user's second factor can bypass password authentication to log in as that user on the mbCONNECT24 platform.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-3091?
CVE-2025-3091 is a high-severity authentication bypass vulnerability in Helmholz mbCONNECT24, published on 24 Jun 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
An low privileged remote attacker in possession of the second factor for another user can login as that user without knowledge of the other user`s password.
Weakness: CWE-639
Which versions are affected by CVE-2025-3091?
How do I fix CVE-2025-3091?
No fix has been published for CVE-2025-3091 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2025-3091 being exploited?
There is no known exploitation of CVE-2025-3091 in the wild and no public exploit code.
Sources
Also known as GHSA-3mpf-fhf9-62mx.