ByteDance's photo-sharing app Lemon8 and Shanghai-based content-sharing platform RedNote have surged in popularity in the United States as "TikTok refugees" migrate to other platforms ahead of possible bans.

Now a law that could shut down TikTok in the U.S. could put these Chinese social media apps and others gaining attention as alternatives to TikTok in trouble, legal experts say.

As of Wednesday, RedNote — known as Little Red Book in China — It is the number one free app in the US iOS store, with Lemon8 ranking second.

The U.S. Supreme Court is set to rule on the constitutionality of the Protecting Americans from Foreign Adversaries Controlled Apps Act (PAFACA), which would have threatened the TikTok app if its Beijing-based owner ByteDance does not divest. Banned in the United States. Before January 19th.

While the legislation explicitly names TikTok and ByteDance, experts say its scope is broad and could open the door for Washington to target more Chinese apps.

"Chinese social media apps including Lemon8 and RedNote may also eventually be banned under this law," Tobin Marcus, director of U.S. policy and politics at New York research firm Wolfe Research, told CNBC.

If the TikTok ban is upheld, the law is unlikely to allow for potential alternatives from China without some form of divestment, experts told CNBC.

Marcus said PAFACA automatically applies to Lemon8 because Lemon8 is a subsidiary of ByteDance, and RedNote could be subject to the law if its average monthly user base in the U.S. continues to grow.

The legislation prohibits the distribution, maintenance or provision of internet hosting services to any "application controlled by a foreign adversary."

The apps include those associated with ByteDance or TikTok or social media companies controlled by "foreign adversaries" and have been determined to pose significant threats to national security.

Carl Tobias, chair of the Williams School of Law at the University of Richmond, said the language of the legislation is "pretty broad" and will give incoming President Donald Trump room to decide which entities pose a significant threat to national security. .

Lu Xiaomeng, geotechnical director of political risk consulting firm Eurasia Group, told CNBC that even if the implementation and enforcement of the law are delayed, it may prevail. Regardless, she expects Chinese apps to continue to be the subject of increased regulatory action in the U.S. in the future.

"The TikTok case sets a new precedent for Chinese apps to be targeted and potentially shut down," Lu said.

She added that other Chinese apps that may be affected by tighter scrutiny this year include popular Chinese e-commerce platforms Temu and Shein. U.S. officials have accused the apps of posing data risks, accusations similar to those leveled against TikTok.

TikTok's fate rests with the Supreme Court after the platform and its parent company filed a lawsuit against the U.S. government, arguing that invoking PAFACA violated constitutional protections for free speech.

Gautam Hans, a law professor at Cornell University, said TikTok's argument is that the law is unconstitutional as it applies to them specifically, not that it is unconstitutional per se. "So whether TikTok wins or loses, the law may still apply to other companies," he said.

Hans said the law defines permissions broadly enough to apply to a variety of Chinese apps deemed to pose a threat to national security, not just traditional social media apps like TikTok.

At the same time, Trump urged the US Supreme Court to delay the implementation of PAFACA so that he can find a "political solution" after taking office. Democratic lawmakers are also urging Congress and President Joe Biden to extend the Jan. 19 deadline.