CVE-2026-39880 Remnawave Backend has a race condition in HWID device limit allows bypassing max devices
Authenticated users can bypass HWID device limits via a race condition, enabling subscription resale and excessive traffic consumption.
- 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-2026-39880?
CVE-2026-39880 is a medium-severity vulnerability in remnawave backend, published on 8 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Remnawave Backend is the backend for the Remnawave proxy and user management solution. Prior to 2.7.5, a glitch in the HWID device registration logic allows an authenticated user to bypass the configured limit for HWID devices and register more devices than expected, allowing them to resell subscriptions and consume excessive traffic. This vulnerability is fixed in 2.7.5.
Weakness: CWE-362
Which versions are affected by CVE-2026-39880?
It affects 1 product.
Products include Remnawave Remnawave Backend.
How do I fix CVE-2026-39880?
No fix has been published for CVE-2026-39880 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-39880 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39880 exists.
Sources
Also known as GHSA-985p-44h5-v3pq.