Citrix NetScaler Memory Overflow Vulnerability (CVE-2025-7775)

Citrix NetScaler ADC and NetScaler Gateway contain a memory overflow vulnerability that could allow for remote code execution and/or denial of service.

Published Aug 26, 2025 · Updated May 17, 2026

Why patchRisk explained in plain English

Worst-case scenarioIf unpatched

A remote attacker, without authentication, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. Federal agencies are required to remediate by 2025-08-28 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Buffer Overflow (CWE-119) vulnerability in Citrix NetScaler. Memory overflow vulnerability leading to Remote Code Execution and/or Denial of Service in NetScaler ADC and NetScaler Gateway when NetScaler is configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server (OR) NetScaler ADC and NetScaler Gateway 13.1, 14.1, 13.1-FIPS and NDcPP: LB virtual servers of type (HTTP, SSL or HTTP_QUIC) bound with IPv6 services or servicegroups bound with IPv6 servers (OR) NetScaler ADC and NetScaler Gateway 13.1, 14.1, 13.1-FIPS and NDcPP: LB virtual servers of type (HTTP, SSL or HTTP_QUIC) bound with DBS IPv6 services or servicegroups bound with IPv6 DBS servers (OR) CR virtual server with type HDX Exploitation requires remote network access, low attack complexity, no authentication required, and no user interaction required.

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Phishing link

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Malicious file

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Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

●Network Security Team

●Firewall Administrators

●IT Security

●Running netscaler application delivery controller: 12.1 ≤ v < 12.1-55.330, 13.1 ≤ v < 13.1-37.241, 13.1 ≤ v < 13.1-59.22, 14.1 ≤ v < 14.1-47.48; netscaler gateway: 13.1 ≤ v < 13.1-59.22, 14.1 ≤ v < 14.1-47.48

Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2025-08-26 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2025-08-28.

How to patch

Manual remediation steps

Identify affected hosts: query inventory for network-security installs in scope.

Apply the vendor security update referenced in CVE-2025-7775's advisory. No specific KB/version is encoded yet — consult the linked MSRC/vendor URL.

Verify the fix per the vendor's published verification steps.

Document the remediation in your change ticket and re-scan with your vulnerability scanner to confirm closure.

PowerShell automationComing soon

No tested PowerShell script for this entry yet. We’re prioritising automation based on user demand.

References

↗ CVE-2025-7775 ↗ MSRC Advisory ↗ NVD ↗ Vendor Advisory