CVE-2026-40571 NamelessMC: Reactions on private or blocking profile posts can be modified without proper authorization
Authenticated users can modify reactions on private or blocked profile posts in NamelessMC due to missing visibility checks.
- 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-2026-40571?
CVE-2026-40571 is a medium-severity missing authorization vulnerability in NamelessMC Nameless, published on 2 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
NamelessMC is website software for Minecraft servers. In version 2.2.4, `core/classes/Misc/ProfilePostReactionContext.php` only verifies that the wall post exists and does not enforce blocked/private-profile visibility. This means that authenticated low-privileged users can add reactions to private or blocking profile posts. Version 2.2.5 contains a patch.
Weakness: CWE-862
Which versions are affected by CVE-2026-40571?
How do I fix CVE-2026-40571?
No fix has been published for CVE-2026-40571 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-40571 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40571 exists.
Sources
Also known as GHSA-47hr-jj6c-rqf9.