Citrix warns of active exploitation of a critical vulnerability in NetScaler appliances (CVE-2025-6543), causing denial of service. Administrators are urged to update their systems promptly and monitor for suspicious activity. #NetScalerVulnerability #CVE-2025-6543
Keypoints
- The CVE-2025-6543 flaw affects NetScaler ADC and Gateway versions prior to specific updates.
- Exploits have been observed to cause devices to crash and go offline when unmitigated.
- Citrix has issued patches for affected versions, urging immediate application to prevent attacks.
- Another critical flaw, CitrixBleed 2 (CVE-2025-5777), allows session hijacking and has been exploited by ransomware gangs.
- Organizations should monitor for unusual activity and review access controls following these vulnerabilities.