What EVULNABLE says
Listed in the CISA KEV catalog, and Confirmed exploitation in the wild.
Patch This Cycle
CVE-2021-26829
OpenPLC — OpenPLC ScadaBR Cross-site Scripting Vulnerability
CISA KEV · in the CISA KEV catalog since 2025-11-28
The priority band answers “how soon”, not “how bad” — see Methodology for what it weighs and where it abstains.
The evidence behind it
| Measure | Value | Source |
|---|---|---|
| CVSS base score | 5.4 | NVD |
| FIRST EPSS | 0.480 (98.8th pctl) | FIRST |
| Actively exploited | Confirmed | CISA KEV |
| Ransomware campaign use | Unknown or none | CISA KEV |
| CISA remediation deadline | 2025-12-19 — Overdue by 9 months | CISA KEV |
The primary records
This page is an opinion about urgency. Where it and a source of record disagree, the source of record is the record.
Where this sits
CVE-2021-26829 is one of the entries ranked on the priority feed and in the non-Microsoft advisories.