Skip to main content

CVE-2025-6543

Citrix — Citrix NetScaler ADC and Gateway Buffer Overflow Vulnerability

Citrix · CWE-119 · in CISA KEV since 2025-06-30

KEV since 2025 · listed over a yearCISA KEVActively Exploited
75

EVRS 75 of 100 Urgent

Patch This Cycle

Rank 1,016 of 2,960 tracked

Raised to the floor for a confirmed exploited vulnerability.

Download PDF

Why it scores 75

Evidence available: 6 of 7 signals

Listed in the CISA KEV catalog, and an EPSS probability of 0.106.

  • CISA KEVApplied
  • RansomwareDid not apply
  • Vendor exploitationDid not apply
  • EPSSApplied
  • Microsoft Exploitability IndexNot applicable
  • Pre-patch disclosureNo data
  • KEV recencyDid not apply
  • CVSSApplied

The band answers “how soon”, not “how bad”. No data for: Pre-patch disclosure. Why some signals show no data

Fix

Patch or fixed version identified

CISA required action

Fixed in

netscaler application delivery controller: update to 13.1-37.236 or later | netscaler application delivery controller: update to 13.1-59.19 or later | netscaler application delivery controller: update to 14.1-47.46 or later | netscaler gateway: update to 13.1-59.19 or later | netscaler gateway: update to 14.1-47.46 or later

Affected versions

  • netscaler application delivery controller>= 13.1 < 13.1-37.236>= 13.1 < 13.1-59.19>= 14.1 < 14.1-47.46
  • netscaler gateway>= 13.1 < 13.1-59.19>= 14.1 < 14.1-47.46

Remediation

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

Fixed versions from NVD.

Evidence

Each value with its source
MeasureValueSource
CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. 9.2 NVD
FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. 0.106 (95.8th pctl) FIRST EPSS
Actively exploitedWhether a source of record has confirmed attacks using it in the wild. Confirmed CISA KEV
Ransomware campaign useWhether CISA has seen ransomware operators use it. Unknown or none CISA KEV
CISA remediation deadlineThe date US federal agencies must have fixed or mitigated it. 2025-07-21 · KEV since 2025 · listed over a year CISA KEV
Public exploit moduleA module existing is not the same as active exploitation. None known Metasploit
EUVD cross-referenceENISA's record: CVSS 9.2 (v4.0), assigned by Citrix. Listed ENISA EUVD

Description

NVD

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

What CISA says to do