MEDIUM CISA KEV

CVE-2021-26829

CVSS v3

5.4

MEDIUM

EPSS Score

13.6%

exploit probability

CISA KEV

Yes

known exploited

Exploitation

—

SSVC status

Description

OpenPLC ScadaBR through 0.9.1 on Linux and through 1.12.4 on Windows allows stored XSS via system_settings.shtm.

CISA Known Exploited Vulnerability

Date Added
11/28/2025
Patch Due Date
12/19/2025
Ransomware Use
Unknown

Technical details

Published
6/11/2021

Frequently asked questions

What is CVE-2021-26829?

OpenPLC ScadaBR through 0.9.1 on Linux and through 1.12.4 on Windows allows stored XSS via system_settings.shtm.

Is CVE-2021-26829 actively exploited?

Yes. CVE-2021-26829 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 12/19/2025.

What is the CVSS score for CVE-2021-26829?

CVE-2021-26829 has a CVSS v3 base score of 5.4 (MEDIUM severity).

Is CVE-2021-26829 affecting your environment?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.

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