Citrix NetScaler ADC and Gateway Out-of-Bounds Read Vulnerability (CVE-2025-5777)
Severity: high · Patch status: unknown · Since 2025-07-10 · CVE-2025-5777
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. CISA added CVE-2025-5777 to its Known Exploited Vulnerabilities catalog on Jul 10, 2025, which means attackers are exploiting it in the wild. CISA reports known use in ransomware campaigns.
What to do
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- US federal agencies must remediate by Jul 11, 2025 (BOD 22-01); treat that as the outer limit.
Sources
All live incidents on Threat Watch