Vulnerability

CVE-2021-26828

High· 8.8KEVCVSS8.8EPSS80%

.rules3/5

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.

Threat signal

100/100

Severe

Severity

high

CVSS

8.8

EPSS

80%

Active

KEV

CISA KEV — actively exploited

171d overdue

AffectedOpenPLC — ScadaBR

Added to KEV

2025-12-03

Federal patch due (BOD 22-01)

2025-12-24

Required action (CISA verbatim)

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

Vendor advisory + references

CISA 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.”

CVSS

v3.1Open in FIRST calculator →

8.8/ 10HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack VectorNetworkExploitable remotely over the internet — no local access needed.
Attack ComplexityLowNo special conditions — exploit works reliably.
Privileges RequiredLowStandard user privileges sufficient.
User InteractionNoneFully automated — no victim action needed.
ScopeUnchangedImpact contained to the vulnerable component.
Confidentiality ImpactHighTotal disclosure of sensitive data.
Integrity ImpactHighTotal compromise of integrity — full data modification possible.
Availability ImpactHighTotal loss of availability — full DoS possible.

EPSS

Exploit prediction · 30-day horizonFIRST.org →

80.0%

probability of exploitation in next 30 days

p99

higher than 99% of all CVEs

3-day trend↑ 1.6pp

Statistically about to be weaponized — top-tier triage urgency.

Vendor VEX

No VEX statements published for CVE-2021-26828. Vendors publish VEX (Vulnerability Exploitability eXchange) to assert per-product whether a CVE is actually exploitable in their distribution.

SSVCAct

Active exploitation with total impact on essential/support systems

exploitation: active
automatable: yes
impact: total
mission: support

Lifecycle

2025-12-03Added to CISA KEVransomware: Unknown
2025-12-03Published
2025-12-24Federal patch due (BOD 22-01)
2026-06-12Last modified1 source

No source-event history recorded yet. New revisions will appear here as ingestors re-fetch this CVE.