CVE-2026-66750 Let's Chat 0.3.0 - 0.4.8 Broken Access Control File Disclosure via GET /files route
Authenticated attackers can download files from private rooms they do not belong to due to missing membership checks in the file retrieval route.
- 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-2026-66750?
CVE-2026-66750 is a medium-severity missing authorization vulnerability in sdelements lets-chat, published on 28 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Let's Chat 0.3.0 through 0.4.8 contains a broken access control vulnerability that allows authenticated attackers to download file attachments from private and password-protected rooms they are not a member of by exploiting missing room membership checks in the file retrieval route. Attackers can enumerate adjacent MongoDB ObjectIds derived from a known file ID to recover files uploaded by other users, as the GET /files/:id/:name route in app/controllers/files.js only enforces login authentication without consulting room membership or the Room.canJoin check.
Weakness: CWE-862
Which versions are affected by CVE-2026-66750?
How do I fix CVE-2026-66750?
No fix has been published for CVE-2026-66750 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-2026-66750 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-66750 exists.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-mf6v-fwp6-46g3.