The Meta-owned messaging app giant said in its security advisory that it fixed the vulnerability, known officially as CVE-2025-55177, which was used alongside a separate flaw found in iOS and Macs, which Apple fixed last week and tracks as CVE-2025-43300.

Apple said at the time that the flaw was used in an “extremely sophisticated attack against specific targeted individuals.” Now we know that dozens of WhatsApp users were targeted with this pair of flaws.

Donncha Ó Cearbhaill, who heads Amnesty International’s Security Lab, described the attack in a post on X as an “advanced spyware campaign” that targeted users over the past 90 days, or since the end of May. Ó Cearbhaill described the pair of bugs as a “zero-click” attack, meaning it does not require any interaction from the victim, such as clicking a link, to compromise their device.

The two bugs chained together allow an attacker to deliver a malicious exploit through WhatsApp that’s capable of stealing data from the user’s Apple device. 

Per Ó Cearbhaill, who posted a copy of the threat notification that WhatsApp sent to affected users, the attack was able to “compromise your device and the data it contains, including messages.”

It’s not immediately clear who, or which spyware vendor, is behind the attacks. 

When reached by TechCrunch, Meta spokesperson Margarita Franklin confirmed the company detected and patched the flaw “a few weeks ago” and that the company sent “less than 200” notifications to affected WhatsApp users. 

The spokesperson did not say, when asked, if WhatsApp has evidence to attribute the hacks to a specific attacker or surveillance vendor.

This is not the first time that WhatsApp users have been targeted by government spyware, a kind of malware capable of breaking into fully patched devices with vulnerabilities not known to the vendor, known as zero-day flaws.

In May, a U.S. court ordered spyware maker NSO Group to pay WhatsApp $167 million in damages for a 2019 hacking campaign that broke into the devices of more than 1,400 WhatsApp users with an exploit capable of planting NSO’s Pegasus spyware. WhatsApp brought the legal case against NSO, citing a breach of federal and state hacking laws, as well as its own terms of service.

Earlier this year, WhatsApp disrupted a spyware campaign that targeted around 90 users, including journalists and members of civil society across Italy. The Italian government denied its involvement in the spying campaign. Paragon, whose spyware was used in the campaign, later cut off Italy from its hacking tools for failing to investigate the abuse.