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.

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation poc

Automatable no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Opensource-socialnetwork
  • Open Source Social Network

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References
Link Providers
https://github.com/opensource-socialnetwork/opensource-socialnetwork cve-icon cve-icon
https://github.com/opensource-socialnetwork/opensource-socialnetwork/blob/48b53f5b95488187715b2d5b5ae46a993267f83d/components/OssnMessages/ossn_com.php#L149-L156 cve-icon cve-icon
https://github.com/opensource-socialnetwork/opensource-socialnetwork/commit/2e9733d8eaafccdaef3d9b498348c8332e51f48b cve-icon cve-icon
https://github.com/opensource-socialnetwork/opensource-socialnetwork/issues/2641 cve-icon cve-icon
https://hackmd.io/@leediay/ossn-idor-message-attachment cve-icon cve-icon
https://www.vulncheck.com/advisories/open-source-social-network-ossn-through-10.1-idor-via-message-attachment-route cve-icon cve-icon
History

Tue, 13 Oct 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Sat, 10 Oct 2026 14:00:00 +0000

Type Values Removed Values Added
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.
Title Open Source Social Network (OSSN) through 10.1 IDOR via Message Attachment Route
First Time appeared Opensource-socialnetwork
Opensource-socialnetwork open Source Social Network
Weaknesses CWE-639
CPEs cpe:2.3:a:opensource-socialnetwork:open_source_social_network:*:*:*:*:*:*:*:*
Vendors & Products Opensource-socialnetwork
Opensource-socialnetwork open Source Social Network
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'}

cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-10-10T13:55:14.834Z

Updated: 2026-10-13T18:29:24.342Z

Reserved: 2026-10-09T15:41:44.133Z

Link: CVE-2026-108164

cve-icon Vulnrichment

Updated: 2026-10-13T18:29:16.781Z

cve-icon NVD

Status : Deferred

Published: 2026-10-10T14:16:37.663

Modified: 2026-10-16T19:18:44.867

Link: CVE-2026-108164

cve-icon Redhat

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