⚠ Actively exploited
Added to CISA KEV on 2025-06-30. Federal agencies required to patch by 2025-07-21. 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..

CVE-2025-6543Improper Restriction of Operations within the Bounds of a Memory Buffer in ADC

Severity
9.2CRITICALNVD
VulnCheck9.3
EPSS
2.3%
top 15.38%
CISA KEV
KEV
Added 2025-06-30
Due 2025-07-21
Exploit
No known exploits
Timeline
PublishedJun 25
KEV addedJun 30
KEV dueJul 21
Latest updateMar 28
CISA 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.

Description

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

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L

Affected Packages4 packages

CVEListV5netscaler/gateway14.147.46+2
NVDcitrix/netscaler_gateway13.113.1-59.19+1
CVEListV5netscaler/adc14.147.46+2

🔴Vulnerability Details

3
GHSA
GHSA-9gqr-6728-fpv3: Memory overflow vulnerability leading to unintended control flow and Denial of Service in NetScaler ADC and NetScaler Gateway when configured as Gatew2025-06-26
VulnCheck
Citrix NetScaler ADC and Gateway Out-of-Bounds Read Vulnerability2025
VulnCheck
Citrix NetScaler ADC and Gateway Buffer Overflow Vulnerability2025

📋Vendor Advisories

1
CISA
Citrix NetScaler ADC and Gateway Buffer Overflow Vulnerability2025-06-30

🕵️Threat Intelligence

12
Hackernews
Citrix NetScaler Under Active Recon for CVE-2026-3055 (CVSS 9.3) Memory Overread Bug2026-03-28
Hackernews
Citrix Urges Patching Critical NetScaler Flaw Allowing Unauthenticated Data Leaks2026-03-24
Tenable
CVE-2025-7775 Citrix RCE Zero-day2025-08-26
Talos
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