Citrix NetScaler ADC and Gateway contain an out-of-bounds read vulnerability due to insufficient input validation. This vulnerability can lead to memory overread when the NetScaler is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server.
Citrix · NetScaler ADC and Gateway
Known ransomware use: Known
Follow the source advisory and validate exposure in your environment.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Recent reporting that mentions CVE-2025-5777.
Threat actors associated with the Anubis ransomware operation have been observed exploiting the Citrix Bleed 2 (CVE-2025-5777) vulnerability to obtain initial access
The same APT hammered critical bugs in Citrix NetScaler (CVE-2025-5777) and the Cisco Identity Service Engine (CVE-2025-20337) in a sign of growing adversary interest in identity and access management systems.
An advanced threat actor exploited the critical vulnerabilities "Citrix Bleed 2" (CVE-2025-5777) in NetScaler ADC and Gateway, and CVE-2025-20337 affecting Cisco Identity Service Engine (ISE) as zero-days to deploy custom malware. [...]
A critical Citrix NetScaler vulnerability, tracked as CVE-2025-5777 and dubbed "CitrixBleed 2," was actively exploited nearly two weeks before proof-of-concept (PoC) exploits were made public, despite Citrix stating that there was no evidence of attacks. [...]
Ransomware Group Among Attackers Focused on Exploiting Citrix Netscaler FlawSecurity experts warn that attackers have ramped up their collective attempts to find and exploit Citrix NetScaler devices that remain unpatched. Cloud Security Group patched CVE-2025-5777, a flaw also known as "Citrix Bleed 2," nearly four weeks ago with a software update.
The U.S. Cybersecurity & Infrastructure Security Agency has confirmed active exploitation of the CitrixBleed 2 vulnerability (CVE-2025-5777) in Citrix NetScaler ADC and Gateway and is giving federal agencies one day to apply fixes. [...]
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Thursday added a critical security flaw impacting Citrix NetScaler ADC and Gateway to its Known Exploited Vulnerabilities (KEV) catalog, officially confirming the vulnerability has been weaponized in the wild
Add CISA to the list The US Cybersecurity and Infrastructure Security Agency has added its weighty name to the list of parties agreeing that CVE-2025-5777, dubbed CitrixBleed 2 by one researcher, has been under exploitation and abused to hijack user sessions.…
Researchers have released proof-of-concept (PoC) exploits for a critical Citrix NetScaler vulnerability, tracked as CVE-2025-5777 and dubbed CitrixBleed2, warning that the flaw is easily exploitable and can successfully steal user session tokens. [...]
NetScaler vendor issued a patch but otherwise, stony silence Multiple exploits are circulating for CVE-2025-5777, a critical bug in Citrix NetScaler ADC and NetScaler Gateway dubbed CitrixBleed 2, and security analysts are warning a "significant portion" of users still haven't patched.…
A critical NetScaler ADC and Gateway vulnerability dubbed "Citrix Bleed 2" (CVE-2025-5777) is now likely exploited in attacks, according to cybersecurity firm ReliaQuest, seeing an increase in suspicious sessions on Citrix devices. [...]
A critical NetScaler ADC and Gateway vulnerability dubbed "Citrix Bleed 2" (CVE-2025-5777) is now likely exploited in attacks, according to cybersecurity firm ReliaQuest, seeing an increase in suspicious sessions on Citrix devices. [...]