CVE-2025-6543Memory overflow vulnerability leading to unintended control flow and Denial of Service

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

9.2 CRITICALEPSS 10.43%⚡ Known Exploited (CISA KEV)NVD: Analyzed

Last updated: 2026-06-17 10:02 UTC

OverviewCVSS details

9.2CRITICALCVSS 4.0

Score source: Citrix (CNA)
NVD status: Analyzed
Published: Jun 25, 2025
Assigner: Citrix

Affected

ADC (NetScaler)

Versions: 14.1 before 47.46 · 13.1 before 59.19
Fixed in: 47.46, 59.19, 37.236

+1 more product →

Exploitation

Public exploit: None listed
CISA KEV: Listed · Jun 30, 2025
KEV due date: Jul 21, 2025
Ransomware use: Unknown
SSVC: Exploitation active · Automatable no · Impact total

EPSS · FIRST, scored Nov 8

10.43%chance of exploitation in 30 days

Higher than 95.77% of CVEs

CVSS 4.0 · Citrix (CNA)

9.2Critical

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

Attack vector: Network
Attack complexity: High
Attack requirements: Present
Privileges required: None
User interaction: None
Confidentiality impact: High
Integrity impact: High
Availability impact: High
Confidentiality (other systems): Low
Integrity (other systems): Low
Availability (other systems): Low

CVSS 3.1 · NVD

9.8Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

NVD status: Analyzed

Overview Affected Products References

NVD CVE.org

Overview

Severity

Score	Severity	Version	Vector String
9.2	CRITICAL	4.0Citrix (CNA)	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
9.8	CRITICAL	3.1NVD	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA required action

⚡ Known exploited · remediation due Jul 21, 2025

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

Details

CVE ID: CVE-2025-6543
Status: Analyzed
Assigner (CNA): Citrix
Published: Jun 25, 2025
Last modified: 2026-06-17 10:02 UTC
Weaknesses: CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer

Sources

Refreshed hourly from the sources above. Last fetched 2026-11-09 12:17 UTC.