CVE-2026-41418 4ga Boards: User Enumeration via Timing Side-Channel in Authentication Endpoint
Attackers can enumerate valid users by measuring response time differences in the login endpoint, exposing user accounts.
- 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-2026-41418?
CVE-2026-41418 is a medium-severity vulnerability in RARgames 4gaBoards, published on 24 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
4ga Boards is a boards system for realtime project management. Prior to 3.3.5, 4ga Boards is vulnerable to user enumeration via a timing side-channel in the login endpoint (POST /api/access-tokens). When an invalid username/email is provided, the server responds immediately (~17ms average). When a valid username/email is provided with an incorrect password, the server first performs a bcrypt.compareSync() operation (~74ms average) before responding. This ~4.4× timing difference is trivially detectable even over a network — a single request suffices. This vulnerability is fixed in 3.3.5.
Weakness: CWE-208
Which versions are affected by CVE-2026-41418?
How do I fix CVE-2026-41418?
No fix has been published for CVE-2026-41418 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-41418 being exploited?
There is no known exploitation of CVE-2026-41418 in the wild and no public exploit code.
Sources
Also known as GHSA-8mj9-p99h-jhxp.