CVE-2021-26829

scadabr

Published 11 Jun 2021 · updated 17 Jun 2026 · Analyzed

5.4 Medium · CVSS 3.1, NVD

Exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on 28 Nov 2025, with a remediation deadline of 19 Dec 2025 for US federal agencies.

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

Description

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

References

forum.scadabr.com.br/t/report-falhas-de-seguranca-em-versoes-do-scadabr/3615/4 · Vendor Advisory
youtu.be/Xh6LPCiLMa8 · Exploit, Third Party Advisory
www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26829 · US Government Resource
www.forescout.com/blog/anatomy-of-a-hacktivist-attack-russian-aligned-group-targets-otics/ · Third Party Advisory