CVE-2021-26828

HIGHNVD 8.89.0▲Trending — 4 sources updated this weekExploited in the wild

8.8

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.

CVSS v3: 8.8
EG Score: 9.0(high)
EPSS: 99.1%
KEV: ⚠ Exploited

Published

June 11, 2021

Last Modified

December 4, 2025

Advisory Details (4)

Auto-updated Jun 2, 2026

⚠️ Active exploitation confirmed. Patch available. Sources: github_pr, cisa.

cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26828

github_pr Patch Available

#2173 Fixed import project CVE-2021-26828 - added filtering, for grag…

Patch available: SCADA-LTS/Scada-LTS v2.7.1 (PR #2174 merged 2022-04-27)

https://github.com/SCADA-LTS/Scada-LTS/pull/2174

generic

https://youtu.be/k1teIStQr1A

generic

[REPORT] Falhas de segurança em versões do ScadaBR - #4 de h3v0x - ScadaBR - Geral - ScadaBR

http://forum.scadabr.com.br/t/report-falhas-de-seguranca-em-versoes-do-scadabr/3615/4

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-434Unrestricted Upload of File with Dangerous Type

Data Freshness Timeline

(refreshed 20× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-04 17:53 UTCEG score recompute
2026-06-04 17:53 UTCGHSA enrichment
2026-06-04 13:59 UTCEG score recompute
2026-06-04 13:59 UTCGHSA enrichment
2026-06-04 13:10 UTCepss_batch
2026-06-04 13:10 UTCepss_batch
2026-06-04 10:05 UTCEG score recompute
2026-06-04 10:05 UTCGHSA enrichment
2026-06-04 06:11 UTCEG score recompute
2026-06-04 06:11 UTCGHSA enrichment
2026-06-04 02:17 UTCEG score recompute
2026-06-04 02:17 UTCGHSA enrichment
2026-06-03 22:23 UTCEG score recompute
2026-06-03 22:23 UTCGHSA enrichment
2026-06-03 19:09 UTCkev_newly_listed
2026-06-03 18:29 UTCEG score recompute
2026-06-03 18:29 UTCGHSA enrichment
2026-06-03 14:35 UTCEG score recompute
2026-06-03 14:35 UTCGHSA enrichment
2026-06-03 10:41 UTCEG score recompute

Publicly available exploits

(2 references)

Working exploit code is in the public domain (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

GitHub PoCridpath/CVE-2021-26828-Ultimate
First seen May 30, 2025
ScadaFlare Authenticated RCE Exploit Framework for ScadaBR (CVE-2021-26828) OpenPLC ScadaBR
Open source ↗
GitHub PoChev0x/CVE-2021-26828_ScadaBR_RCE
First seen Mar 31, 2021
Open source ↗

Frequently asked(6)

What is CVE-2021-26828?

CVE-2021-26828 is a high vulnerability published on June 11, 2021. 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.

When was CVE-2021-26828 disclosed?

CVE-2021-26828 was first published in the National Vulnerability Database on June 11, 2021, with the most recent update on December 4, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-26828 actively exploited?

Yes. CISA added CVE-2021-26828 to the Known Exploited Vulnerabilities catalog on December 3, 2025, affecting OpenPLC ScadaBR. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.

What is the CVSS score of CVE-2021-26828?

CVE-2021-26828 has a CVSS v3 base score of 8.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.

Which products are affected by CVE-2021-26828?

CVE-2021-26828 affects OpenPLC ScadaBR. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.

How do I remediate CVE-2021-26828?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-26828, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-26828

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CVE-2021-26828

📅 Published

🔄 Last Modified

📋 Advisory Details (4)