Is CVE-2021-26828 actively exploited?

Yes. CVE-2021-26828 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2021-26828 be exploited remotely?

The attack vector of CVE-2021-26828 has not been classified yet.

What is the CVSS score of CVE-2021-26828?

CVE-2021-26828 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2021-26828

HIGHCISA KEVIN THE WILD

CVE-2021-26828

Published: December 3, 2025

EPSS:80.02%probability of exploitation in 30 daysPercentile:99.1th

Official Description

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 view_edit.shtm.

NVD Source

CISA KEV Advisory

OpenPLC ScadaBR Unrestricted Upload of File with Dangerous Type Vulnerability

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 view_edit.shtm.

Added to KEV: 2025-12-03Federal patch deadline: 2025-12-24

Required Action (CISA)

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

Risk Analysis

OpenPLC ScadaBR contains a vulnerability that permits remote authenticated users to upload and execute dangerous JSP files. This could lead to arbitrary code execution on the system. The high EPSS score of 0.80017 indicates a high likelihood of exploitation, and its inclusion in CISA's KEV confirms active exploitation.

This vulnerability is actively exploited in the wild, as confirmed by its presence in CISA's KEV. An authenticated attacker can exploit this remotely.

Recommended Action

Implement strict access controls for ScadaBR and ensure only trusted users have upload permissions. Regularly review and update the ScadaBR application to the latest secure version.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2021-26828 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2021-26828 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.