OpenPLC ScadaBR Unrestricted Upload of File with Dangerous Type Vulnerability (CVE-2021-26828)
Severity: high · Patch status: patched · Since 2025-12-03 · CVE-2021-26828
OpenPLC ScadaBR contains an unrestricted upload of file with dangerous type vulnerability that allows remote authenticated users to upload and execute arbitrary JSP files via viewedit.shtm. CISA added CVE-2021-26828 to its Known Exploited Vulnerabilities catalog on Dec 3, 2025, which means attackers are exploiting it in the wild.
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.
- US federal agencies must remediate by Dec 24, 2025 (BOD 22-01); treat that as the outer limit.
Sources
All live incidents on Threat Watch