Insecure Direct Object Reference in openSIS Classic Messaging Module
CVE-2026-8406

7.1HIGH

Key Information:

Vendor

Os4ed

Status
Opensis-classic
Vendor
CVE Published:
11 June 2026

What is CVE-2026-8406?

The messaging module in openSIS Classic 9.3 is vulnerable to an insecure direct object reference flaw. Authenticated users with access can exploit this vulnerability by manipulating the mail_id parameter while requesting sent-message details. This may lead to unauthorized access to sensitive information, allowing users to view messages they shouldn't have permissions for.

Affected Version(s)

openSIS-Classic Windows 9.3

References

https://fluidattacks.com/es/advisories/melanie
third-party-advisory
https://github.com/OS4ED/openSIS-Classic/commit/c45d43146...
patch
https://github.com/OS4ED/openSIS-Classic
product

CVSS V4

Score:
7.1
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Daniel Celis
.