OpenPLC · ScadaBR

CVE-2021-26829

OpenPLC ScadaBR Cross-site Scripting Vulnerability

Exploited in attacks Medium 5.4 Attack chance: 48%

What it is

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

CISA: OpenPLC ScadaBR contains a cross-site scripting vulnerability via system_settings.shtm.

What to do

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Deadline for US federal agencies: December 19, 2025

Added to the CISA list: November 28, 2025
Published: June 11, 2021
Severity: Medium 5.4 CVSS 3.1
Chance of attacks in the next 30 days (EPSS): 48% in the top 1.2% of all known vulnerabilities
Weakness: CWE-79
More details: NVD · CVE.org · CISA

All references (2)

More exploited flaws from OpenPLC

Added	Vulnerability	Product	Severity	Attack chance
Dec 3, 2025	Unrestricted Upload of File with Dangerous TypeCVE-2021-26828	ScadaBR	High 8.8	39%

All of them →

Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.