CVE-2026-108164 Open Source Social Network (OSSN) through 10.1 IDOR via Message Attachment Route
Authenticated attackers can read other users' private message attachments by guessing file GUIDs in the attachment 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-2026-108164?
CVE-2026-108164 is a high-severity missing authorization vulnerability in opensource-socialnetwork, published on 10 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Open Source Social Network (OSSN) through 10.1 contains an insecure direct object reference vulnerability in components/OssnMessages/ossn_com.php that allows authenticated users to read other users' private message attachments. Attackers can request the /messages/attachment/{guid} route with sequential or guessed file GUIDs to retrieve attachments from private conversations without sender or recipient verification.
Weakness: CWE-639
Which versions are affected by CVE-2026-108164?
How do I fix CVE-2026-108164?
No fix has been published for CVE-2026-108164 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-2026-108164 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-108164 exists.
Sources
Also known as GHSA-6qx6-fpjx-pg68.