---
title: "CVE-2026-91107: openSIS Classic - Broken Access Control"
description: "openSIS Classic 9.3 contains a broken access control vulnerability caused by improper authorization in the School Information update path, letting authenticated users with teacher role reset arbitrary staff passwords, exploit requires teacher role authentication."
url: https://panop.io/threat-heartbeat/CVE-2026-91107/
---

# CVE-2026-91107 openSIS Classic - Broken Access Control

openSIS Classic 9.3 contains a broken access control vulnerability caused by improper authorization in the School Information update path, letting authenticated users with teacher role reset arbitrary staff passwords, exploit requires teacher role authentication.

CVSS base score 9.3 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.24% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-91107)

## Details

Type

Broken Access Control

Impact

Privilege Escalation, Broken Access Control

CVSS vector

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Published

5 October 2026

Updated

15 October 2026

Weakness

[CWE-639](https://cwe.mitre.org/data/definitions/639.html)

## Vendor fix

Update to the latest version with proper authorization checks.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-91107](https://nvd.nist.gov/vuln/detail/CVE-2026-91107)
- [https://fluidattacks.com/advisories/hearts](https://fluidattacks.com/advisories/hearts)
- [https://github.com/OS4ED/openSIS-Classic](https://github.com/OS4ED/openSIS-Classic)
- [https://github.com/OS4ED/openSIS-Classic/commit/24bb530391a67c114cd4fe3dff65da7e070f5ed1](https://github.com/OS4ED/openSIS-Classic/commit/24bb530391a67c114cd4fe3dff65da7e070f5ed1)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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