Critical 9.3Published Oct 5, 2026

CVE-2026-91107openSIS Classic 9.3 - Insecure Direct Object Reference (IDOR)

Updated under an hour ago (2026-10-19 07:10 UTC)

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

EPSS puts the chance of exploitation in the next 30 days at 0.24%, higher than 14% of scored CVEs.

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Every CVE for OS4ED openSIS-Classic

Exploited in the last 30 days

openSIS Classic 9.3 allows an authenticated user with the built-in teacher role can select an arbitrary staff record through staff_id and cause the School Information update path to reset that selected account's password.

CVSS: 9.3 CRITICAL (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N
Weakness (CWE): CWE-639
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.24% (percentile 14)
Assigned by: Fluid Attacks
NVD analysis: Awaiting Analysis
Record last updated: Oct 6, 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

https://fluidattacks.com/advisories/heartsthird-party-advisory
https://github.com/OS4ED/openSIS-Classicproduct
https://github.com/OS4ED/openSIS-Classic/commit/24bb530391a67c114cd4fe3dff65da7e070f5ed1patch

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.