Risk Letters

Exploited vulnerability

CVE-2025-5777

TLP:CLEAR

Citrix NetScaler ADC and Gateway Out-of-Bounds Read Vulnerability

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.

Facts

  • Vendor: Citrix
  • Product: NetScaler ADC and Gateway
  • CVSS: 9.3
  • EPSS (probability of exploitation within 30 days): 100 %
  • On CISA's Known Exploited Vulnerabilities list since: 10 July 2025
  • First known exploitation: 10 July 2025
  • Used in ransomware campaigns (per CISA): Yes
  • CISA's deadline for US federal agencies: 11 July 2025
  • Weakness: CWE-125
  • First seen by Risk Letters: 10 July 2025

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Data: NVD (public domain), CISA KEV, FIRST EPSS, MITRE ATT&CK, AlienVault OTX. NVD