High 7.1Published Jun 11, 2026

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

Updated under an hour ago (Oct 27, 2026, 3:10 PM ET)

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It affects OS4ED openSIS-Classic. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for OS4ED openSIS-Classic

Exploited in the last 30 days

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.

CVSS: 7.1 HIGH (v4.0, CNA)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
Weakness (CWE): CWE-639
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Fluid Attacks
NVD analysis: Deferred
Record last updated: Jun 11, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

OS4ED openSIS-Classic os4ed:opensis_classic (from the name)	9.3	CNA record

References

References

https://fluidattacks.com/es/advisories/melanie	third-party-advisory
https://github.com/OS4ED/openSIS-Classic/commit/c45d43146167324bae06bdf09de3e4bd2e5e478f	patch
https://github.com/OS4ED/openSIS-Classic	product

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.