Skip to content
CVE Tracker
  • Newest CVEsPage
  • Recently added to KEVPage
  • Rising exploitation (EPSS)Page
  • Weekly digestPage
  • StatisticsPage
  • WatchlistPage
  • API documentationPage
  • MCP serverPage
  • Data sourcesPage
  • ChangelogPage
  • AboutPage
  • How it's builtPage
Back

CVE-2025-6543

Memory overflow vulnerability leading to unintended control flow and Denial of Service

Critical9.2Known exploitedEPSS 10.4%
Published
Updated
Reserved
Assigned by
Citrix

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

Exploited in the wild

CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Citrix NetScaler ADC and Gateway Buffer Overflow Vulnerability.

Added
30 Jun 2025
Fix due (US federal)
21 Jul 2025
Used by ransomware
Not known

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

Scores

CVSS scores of CVE-2025-6543, by who scored it
Scored byCVSSScoreVector
CitrixCNA (assigner)4.0Critical9.2CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L
NVDNVD · Analyzed4.0Critical9.2CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS (exploitation in 30 days)
10.4% · top 4.2% of all CVEs (6 Nov 2026)
CISA SSVC
Exploitation: active · Automatable: no · Technical impact: total
Loading the EPSS history…

The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.2.

Weakness

Affected products

  • NetScaler · ADC

    • affected 14.1 – < 47.46
    • affected 13.1 – < 59.19
    • affected 13.1 FIPS and NDcPP – < 37.236

  • NetScaler · Gateway

    • affected 14.1 – < 47.46
    • affected 13.1 – < 59.19
    • affected 13.1 FIPS and NDcPP – < 37.236

References (2)

Sources

The same CVE in the primary databases and aggregators, to check against.

Badge for a README or a ticket

CVE-2025-6543 badge
[![CVE-2025-6543](https://trackcve.app/badge/CVE-2025-6543.svg)](https://trackcve.app/cve/CVE-2025-6543)

Record last updated .