Citrix NetScaler ADC and Gateway Buffer Overflow Vulnerability
NetScaler — ADC
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
9.8
10.1%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Published
- Jun 25, 2025
- Modified
- Jun 17, 2026
- Added to KEV
- Jun 30, 2025
- Federal patch due
- Jul 21, 2025
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.
Weakness classification
Affected packages
Proof-of-concept & exploitation references
3 foundWeaponization
Public repositories whose name or description references CVE-2025-6543, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit - cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
- abrewer251/CVE-2025-6543_CitrixNetScaler_PoC★ 6
Multi-host, multi-port scanner and auditor for CVE-2025-6543-affected NetScaler devices. Supports SNMP and SSH enumeration with optional CSV reporting and exploit stubs.
updated Jul 26, 2026
- grupooruss/Citrix-cve-2025-6543★ 5
Script para determinar si Citrix es vulnerable al CVE-2025-6543
updated Jun 22, 2026
- lex1010/CVE-2025-6543★ 0
Citrix Bleed 2 PoC
updated Jun 30, 2025
References
Frequently asked questions
What is CVE-2025-6543?
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
How severe is CVE-2025-6543?
CVE-2025-6543 has a CVSS base score of 9.8 out of 10 (CVSS 3.1).
Is CVE-2025-6543 actively exploited in the wild?
Yes. CVE-2025-6543 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Jun 30, 2025, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2025-6543?
10.1% - meaning FIRST.org's EPSS model estimates a 10.1% probability this vulnerability will be exploited in the wild within 30 days (95% percentile among all scored CVEs).
Is there exploit tooling available for CVE-2025-6543?
We found 3 public GitHub repositories referencing CVE-2025-6543, though none matched a known Nuclei template or Metasploit module at last check. Review each one before relying on it - see the proof-of-concept section above.
What type of vulnerability is CVE-2025-6543?
CVE-2025-6543 is classified under CWE-119 (CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer).
Cross-checked against
Impactr finds and proves whether CVE-2025-6543 - or flaws like it - are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.
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