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Findings

CVE-2025-6543

Citrix NetScaler ADC and Gateway Buffer Overflow Vulnerability

Published Jun 25, 2025 · updated Jun 17, 2026 · citrix netscaler application delivery controller

Citrix NetScaler ADC and Gateway contain a buffer overflow vulnerability leading to unintended control flow and Denial of Service. NetScaler must be configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server.

Timeline

Detection, updates, and resolution for this record.

  1. Jun 25, 2025 · Catalog

    Detected

    Citrix NetScaler ADC and Gateway contain a buffer overflow vulnerability leading to unintended control flow and Denial of Service. NetScaler must be configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server.

  2. Jun 30, 2025 · CISA KEV

    Known exploited

    Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

  3. Jul 21, 2025 · CISA KEV

    Remediation due

    Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

  4. Jun 17, 2026 · Catalog

    Updated

    Citrix NetScaler ADC and Gateway contain a buffer overflow vulnerability leading to unintended control flow and Denial of Service. NetScaler must be configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server.

Required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

CISA due date Jul 21, 2025

Affected

  • cpe citrix/netscaler application delivery controllerversion unspecified
  • cpe citrix/netscaler gatewayversion unspecified
  • vendor Citrix NetScaler ADC and Gatewayversion unspecified

Sources

  • CISA KEVCVE-2025-6543

    Citrix NetScaler ADC and Gateway contain a buffer overflow vulnerability leading to unintended control flow and Denial of Service. NetScaler must be configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server.

    cisa.gov
  • CVE.orgCVE-2025-6543

    Official CVE identifier

    cve.org
  • FIRST EPSSCVE-2025-6543

    30-day exploitation probability 10.6%

    first.org
  • NIST NVDCVE-2025-6543

    Memory overflow vulnerability leading to unintended control flow and Denial of Service in NetScaler ADC and NetScaler Gateway when configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server

    nvd.nist.gov

References