Nuclear weapons systems are at "relatively high" risk of falling victim to cyberattacks, a think tank has warned, which could lead to "inadvertent" missile launches.
Chatham House's study has identified a "number of vulnerabilities" in systems across the world, which leaves them open to attacks from malware and viruses.
The UK, US, Russia, France, China, India, Pakistan, Israel and North Korea all have nuclear weapons, according to the 2014 Stockholm International Peace Research Institute report.
The Chatham House authors suggest that a state that is unaware its systems are being interfered with could make decisions based on false information.
The study's authors state: "The likelihood of attempted cyberattacks on nuclear weapons systems is relatively high and increasing...
"Cyber vulnerabilities within nuclear weapons systems and structures present a whole set of dangers and risks.
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"At best, cyber insecurity in nuclear weapons systems is likely to undermine trust and confidence in military capabilities and in the nuclear weapons infrastructure.
"At worst, cyberattacks could lead to deliberate misinformation and the inadvertent launch of nuclear weapons."
The authors say a mistaken missile launch could cause a "significant loss of life", with the report urging governments of nuclear-armed states to be open about their discussions on an issue which requires "urgent attention".
"After all, it is the public that will pay the ultimate price for complacency regarding cyber-security of nuclear weapons systems," it adds.
The findings also highlight reports the US may have infiltrated parts of North Korea's missile systems in 2016, resulting in test failures.