Huawei has failed to adequately tackle security flaws in equipment used in the UK’s telecoms networks despite previous complaints, said an official report.
It also flagged that a vulnerability “of national significance” had occurred in 2019 but been fixed before it could be exploited.
The assessment was given by an oversight board, chaired by a member of the cyber-spy agency GCHQ.
It could influence other nations weighing up use of Huawei’s kit.
According to the report GCHQ’s National Cyber Security Centre (NCSC) had seen no evidence that Huawei had made a significant shift in its approach to the matter.
It added that while some improvements had been made, it had no confidence they were sustainable.
As a result, it concluded, the board could only provide “limited assurance that all risks to UK national security” could be mitigated in the long-term.
The government announced, in July, that due to US sanctions Huawei would eventually be excluded from the new 5G telecoms network by 2027, but the Chinese company can continue to play a role in older mobile networks and fixed broadband.
The US’s argument was that using Huawei’s equipment creates a risk of the Chinese state carrying out espionage or sabotage, something the company has always denied.