CVE-2026-108164

Open Source Social Network (OSSN) through 10.1 IDOR via Message Attachment Route

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.

Affected

opensource-socialnetwork

CVSS v4.0 VULNCHECK

7.1 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 VULNCHECK

6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS

0.26% chance of exploitation in the next 30 days, 16th percentile

Published

2026-10-10

Updated

2026-10-13

Proof-of-concept exploits (1)

• https://hackmd.io/@leediay/ossn-idor-message-attachment

References

• CVE Record
• NVD entry