The bulletin includes six NetScaler issues, but attention is centered on a high-severity flaw with similarities to earlier actively exploited bugs.

The vendors disclosed and patched the defects last summer, but not before advanced attackers exploited the vulnerabilities to likely gain prolonged access for espionage, according to Amazon.

The vendor, which has been widely targeted, said the memory-overflow vulnerability can result in remote-code execution or denial of service.

The number of Citrix customers impacted by CVE-2025-5777 remains unknown, but researchers have already observed more than 11.5 million attack attempts, targeting thousands of sites.

The vendor disclosed the critical zero-day in NetScaler ADC and NetScaler Gateway nine days after it warned of a pair of defects in the same products.

Exploited vulnerabilities have turned up in Ivanti products 16 times since 2024. That’s more than any other vendor in the network edge device space.

Chinese hackers are using known vulnerabilities to breach a multitude of victims.

Chinese Ministry of State Security-linked actors are actively targeting U.S. government agencies, according to a new alert.

The bugs are in Citrix software that allows clients to remotely connect to corporate networks with their mobile phones.

There haven’t been any reports of malicious hackers exploiting the vulnerabilities, according to Citrix's CISO.