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NVD / CVE Program· CNA mitre

CVE-2021-26828: 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…

HighCVSS 8.8 · v3.1KEVWeaponized No fix recorded

Noroxi assessment

Priority: This week (action score 77/100)

  • CISA has confirmed exploitation in the wild (Dec 3, 2025). Remediation deadline for US federal agencies: Dec 24, 2025.
  • Probability of exploitation in the next 30 days: 39% (FIRST EPSS); higher than 98.6% of all records.
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • No fixed version is recorded, but the references include a patch (commit or PR) link.

Don’t wait for the next maintenance window. See the fix and affected versions sections below.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

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.

Published
Jun 11, 2021
Updated
Jun 16, 2026
EPSS
39.0% · 98th percentile

Report tools

JSON

Action score

77

This week

Don’t wait for the next maintenance window.

CVSS
35 / 40 · 8.8 / 10
CISA KEV
30 / 30 · Listed
EPSS
12 / 30 · 39.0%

CISA SSVC decision

Exploitation
active
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Dec 3, 2025. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Dec 24, 2025.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2021-26828

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
scadabrscadabr
linuxlinux kernel
microsoftwindows

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • scadabr scadabrup to 0.9.1 inclusive
  • scadabr scadabrup to 1.12.4 inclusive

Same product

scadabr: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-26829OpenPLC ScadaBR through 0.9.1 on Linux and through 1.12.4 on Windows allows stored XSS via system_settings.shtm.KEV
    65This week
  • CVE-2026-9645ScadaBR Authenticated Remote Code Execution
    39Monitor
  • CVE-2026-8602Missing authentication for critical function in ScadaBR
    35Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2019-16321Sep 15, 2019 · ScadaBR 1.0CE, and 1.1.x through 1.1.0-RC, has XSS via a request for a nonexistent resource, as demonstrated by the dwr/test/ PATH_INFO.
    24Monitor
  • ← EarlierCVE-2019-16344Oct 14, 2019 · A cross-site scripting (XSS) vulnerability in the login form (/ScadaBR/login.htm) in ScadaBR 1.0CE allows a remote attacker to inject…
    24Monitor
  • Later →CVE-2025-70973Mar 9, 2026 · ScadaBR 1.12.4 is vulnerable to Session Fixation.
    19Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Proof-of-concept repository on GitHub ×3

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHub3 repositories2021-03-31 → 2026-10-09

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. First PoC-72 d
  2. Published
  3. CISA KEV+1636 d
  4. TodayNov 14, 2026+1982 d

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Not on record for this CVE: EPSS history · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-434 · Unrestricted Upload of File with Dangerous Type

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records