CISA Adds Actively Exploited XSS Bug in OpenPLC ScadaBR
⚠️ CISA has added an actively exploited cross-site scripting flaw, CVE-2021-26829, to its Known Exploited Vulnerabilities catalog after reports of operational abuse against OpenPLC ScadaBR. The XSS affects Windows 1.12.4 and Linux 0.9.1 via system_settings.shtm and was used to deface HMI pages and disable logs. Federal civilian agencies must remediate by December 19, 2025; operators should apply vendor fixes, change default credentials, enable logging and monitor for web-layer manipulation and outbound callbacks.
