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

> CVE-2025-6543: Memory overflow vulnerability leading to unintended control flow and Denial of Service. CVSS 9.8 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2025-6543
Last updated: 2026-06-17T10:02:07Z

- Published: 2025-06-25 12:49 UTC · Updated: 2026-06-17 10:02 UTC · Assigner: Citrix
- CVSS: 9.8 (CVSS 3.1) · Severity: Critical · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS: 10.4%, 96th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2025-06-30, federal due date 2025-07-21, ransomware use: Unknown
- CWE: CWE-119

## 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

## 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.

## Affected vendors and products

- NetScaler: ADC
- NetScaler: Gateway

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2025-6543)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2025-6543)
- [https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX694788](https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX694788)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2025-6543 · Markdown: https://rewindex.com/cve/CVE-2025-6543.md · JSON: https://rewindex.com/api/v1/cves/CVE-2025-6543 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:00:30.437Z