US cyber defence agency warns of water attacks after Minnesota targeted

July 31, 2026

The US Cybersecurity and Infrastructure Security Agency has issued an alert about a surge in cyberattacks against water and wastewater facilities across the country. Hackers are compromising programmable logic controllers that manage these systems, locking out legitimate operators by changing access credentials. The warning follows a coordinated assault on over 30 Minnesota water systems in late July, which forced some communities to issue boil water advisories and switch to manual operations.

Who is affected

More than 30 community water systems in Minnesota
Operators of water and wastewater systems who have been locked out
Communities that received boil water notices
The 152,000 public drinking water systems and 16,000+ wastewater treatment systems across the US
Users of Rockwell Automation PLCs and devices from other manufacturers

What action is being taken

CISA is issuing warnings about the increase in cyberattacks
Water systems are being operated manually as a workaround
US investigators are examining whether Iran may be responsible for the Minnesota attacks
Federal government is evaluating the Minnesota activity in the broader national context
Federal government is leading efforts to determine attribution to a specific threat actor

Why it matters

This situation is significant because it represents a direct threat to critical public infrastructure that millions of Americans depend on for safe drinking water and sanitation. The vulnerability of over 168,000 water-related systems nationwide creates massive potential for public health crises, as evidenced by the boil water notices already issued. The possible involvement of a foreign state actor like Iran suggests these attacks could be part of geopolitical tensions rather than isolated criminal activity, raising the stakes considerably for national security.

What's next

No explicit next steps stated in the article

Read full article from source: BBC