Vulnerability in Remnawave Backend
CVE-2026-39880
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.
Vulnerability class: Race Condition
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.0 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (10.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 10th percentile — 10.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
- Remnawave Backend — versions < 2.7.5
- Remnawave Backend
Weakness classification (CWE)
References
- github.com/remnawave/backend/security/advisories/GHSA-985p-44h5-v3pq (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-39880?
- CVE-2026-39880 is a medium-severity vulnerability in Remnawave Backend, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 5.0/10. Published 2026-04-08.
- How severe is CVE-2026-39880?
- Medium severity. CVSS v3 base score is 5.0 out of 10.