What’s Vulnerable › Vulnerabilities

CVE-2026-8406: openSIS Classic 9.3 - Insecure Direct Object Reference in Sent Mail

• Severity: high (CVSS 7.1 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-11 · updated 2026-10-26
• Weakness: CWE-639

Description

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.

Affected products

• OS4ED openSIS-Classic: 9.3

References

• https://fluidattacks.com/es/advisories/melanie
• https://github.com/OS4ED/openSIS-Classic
• https://github.com/OS4ED/openSIS-Classic/commit/c45d43146167324bae06bdf09de3e4bd2e5e478f
• https://fluidattacks.com/es/advisories/melanie

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