CVE-2021-26829
KEVOpenPLC ScadaBR Cross-site Scripting Vulnerability
Description
OpenPLC ScadaBR contains a cross-site scripting vulnerability via system_settings.shtm.
OpenPLC ScadaBR through 0.9.1 on Linux and through 1.12.4 on Windows allows stored XSS via system_settings.shtm.
CVSS 3.1 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:NPublishedJun 11, 2021
Last modifiedJun 17, 2026
Added to KEVNov 28, 2025
Remediation dueDec 19, 2025
References
- forum.scadabr.com.br/t/report-falhas-de-seguranca-em-versoes-do-scadabr/3615/4Vendor Advisory
- youtu.be/Xh6LPCiLMa8ExploitThird Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26829US Government Resource
- forescout.com/blog/anatomy-of-a-hacktivist-attack-russian-aligned-group-targets-otics/Third Party Advisory
0 recent articles mention this CVE
62
Risk assessment · High
Actively exploited. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 311 days
- CVSS
- 5.4 MEDIUM
- EPSS (30-day exploit probability)
- 48.0% · top 1% of all CVEs
- Weakness
- CWE-79
- Attack vector
- Network, remotely reachable
Recommended actions
- 1.Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
- 4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.