Dangerous Type
OpenPLC ScadaBR Unrestricted File Upload Vulnerability
At a glance
Actively exploited in the wild — prioritise confirming exposure.
Medium rather than High: exposure is scored at a default because we cannot see your systems or suppliers. If you run or depend on OpenPLC ScadaBR, treat it as High.
Briefing
- Do not treat uncorroborated claims as confirmed breaches.
Questions to ask IT
- Do we run OpenPLC ScadaBR, and which versions?
- Is any of it reachable from the internet?
- Have we checked whether it has already been used against us?
- If it is not yet patched, what mitigation is in place, and will the fix be done by 11 Nov?
Next steps
- Confirm exposure, mitigation status and any service interruption risk.
Vulnerability facts
Full CVE detail CVE-2021-26828- 8.8 · HighExploitable over the network with a low-privilege account, and no one has to click or open anything. High impact on confidentiality, integrity and availability.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Listed: attacks using it have been seen (on the catalogue since )
- Elevated attack likelihood (~39.1% in 30 days)
- 0.9.1 and earlier, 1.12.4 and earlier
- CVE-2021-26828 has estimated attack likelihood 0.39356 (~39.4% estimated chance of exploitation in 30 days; 98.5th percentile) as of 2026-07-31 — probability signal, not confirmed exploitation
Next steps
- Confirm whether affected products/versions are present and prioritise patching or mitigations
Summary
- 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.
- CVE-2021-26828 is listed in known-exploited catalogue (exploitation in the wild)
- 4% estimated chance of exploitation in 30 days; 98.
- Authoritative catalogues report active exploitation of this vulnerability.
Why this matters in the UK
- Known-exploited catalogue reports exploitation in the wild
Products and services involved
- OpenPLC ScadaBR82% match confidence · CVE-2021-26828
Pulse
Last checked 4d ago · Recheck overdue since 5 Nov 2026, 22:36 UK time · 2 quiet checks collapsed
Suggested changed to 7d.
Listed on the — prioritise confirming exposure and patching.
3 quiet checks hidden.
Sources
OpenPLC ScadaBR Unrestricted Upload of File with Dangerous Type Vulnerability
How we know
Statements extracted from sources. Higher confidence means stronger corroboration.
- ConfirmedHeadline90% confidence
OpenPLC ScadaBR Unrestricted Upload of File with Dangerous Type Vulnerability
- ConfirmedSummary fact75% confidence
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. Affects OpenPLC ScadaBR. Known ransomware campaign use: Unknown. Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- ConfirmedCVE identifier95% confidence
Event involves CVE-2021-26828
- ConfirmedKnown-exploited catalogue98% confidence
CVE-2021-26828 is listed in known-exploited catalogue (exploitation in the wild)
- ConfirmedEstimated attack likelihood95% confidence
CVE-2021-26828 has estimated attack likelihood 0.39356 (~39.4% estimated chance of exploitation in 30 days; 98.5th percentile) as of 2026-07-31 — probability signal, not confirmed exploitation