CVE-2026-15509 Leantime JSON-RPC Endpoint addUser improper authorization
Remote attackers can exploit improper authorization in the JSON-RPC addUser endpoint to escalate privileges or take over accounts.
- 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-2026-15509?
CVE-2026-15509 is a medium-severity missing authorization vulnerability in Leantime, published on 12 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A vulnerability has been found in Leantime up to 3.8.0. This impacts the function editUser/addUser of the component JSON-RPC Endpoint. The manipulation of the argument role leads to improper authorization. The attack is possible to be carried out remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Which versions are affected by CVE-2026-15509?
How do I fix CVE-2026-15509?
No fix has been published for CVE-2026-15509 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-2026-15509 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-15509 exists.
Sources
Also known as GHSA-q4cr-cr7q-hp2f.