CVE-2026-8406 PUBLISHED

openSIS Classic 9.3 - Insecure Direct Object Reference in Sent Mail

Assigner: Fluid Attacks
Reserved: 12.05.2026 Published: 11.06.2026 Updated: 11.06.2026

openSIS Classic 9.3 contains an insecure direct object reference vulnerability in the messaging module. Any authenticated user with access to the messaging module can request sent-message details from modules/messaging/SentMail.php by supplying an arbitrary mail_id value.

Metrics

CVSS 4.0

CVSS 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
CVSS Score: 7.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

Product Status

Vendor	OS4ED
Product	openSIS-Classic
Versions	Default: unaffected Version 9.3 is affected

Credits

Daniel Celis finder

References

Problem Types

CWE-639 Authorization Bypass Through User-Controlled Key CWE

Impacts

CAPEC-21 Exploitation of Trusted Identifiers