CVE-2025-63235 Denial of service in n/a
An attacker can cause a denial of service by sending malformed CONNECT packets that leak resources, potentially triggering the Linux OOM killer.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-63235?
CVE-2025-63235 is a high-severity denial of service vulnerability in n/a, published on 7 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In sol commit 373d848 (2024-12-12), the broker does not fully release resources when handling malformed or duplicate CONNECT packets. When clients send invalid CONNECT packets - either due to repeated attempts or failed authentication - the server may silently drop the connection or send a CONNACK but fail to close the session or deallocate internal resources. This behavior allows an attacker to create numerous half-open connections that consume memory and file descriptors indefinitely, potentially triggering the Linux OOM killer and causing a denial of service.
Weakness: CWE-400
Which versions are affected by CVE-2025-63235?
How do I fix CVE-2025-63235?
No fix has been published for CVE-2025-63235 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-63235 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-63235 exists.
Sources
Also known as GHSA-cc3w-v57m-93mp.