Background exploitation KEV catalog
CVE-2021-26828

OpenPLC ScadaBR Unrestricted Upload of File with Dangerous Type Vulnerability

OpenPLC ScadaBR through 0.9.1 on Linux and through 1.12.4 on Windows allows remote authenticated users to upload and execute arbitrary JSP files via view_edit.shtm.

CheckOps priority index
6.5/10 Patch within 7 days
Severity8.8
Probability3.9
Exploitation3/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 39.1% higher than 98.6% of CVEs
CVSS 3.1 8.8 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:
Exploited for 335 days 03 Dec 2025
CISA due date 24 Dec 2025 for US federal agencies

Exploitation probability EPSS · FIRST

05010026 Sep05 Oct15 Oct24 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 3 / 5

  • KEV catalog (CISA)03 Dec 2025
  • Exploited in EUVD (ENISA)03 Dec 2025
  • Used by ransomwareno
  • EPSS above 10 %39.1%
  • No account, over the networkno

What to do

Fix

Apply the vendor’s fix as soon as it is available.

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

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Affected products

ScadaBR
Weaknesses (CWE)

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

  5. EPSS peak: 39.4%

References

Other exploited vulnerabilities from the same vendor

  • CVE-2021-26829OpenPLC ScadaBR Cross-site Scripting Vulnerability
    5.4 · Background exploitation

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Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities