Citrix NetScaler Zero-Days Exploited in the Wild; Agencies Urge Immediate Restriction
Two unpatched vulnerabilities actively exploited; patches expected next week; organizations advised to shut down or restrict appliances.
Key Takeaways
- Two zero-day vulnerabilities in Citrix NetScaler are being actively exploited in the wild.
- Exploitation was reported in late September 2026, with warnings issued by agencies, researchers, and IT providers.
- Patches are expected to be released next week; organizations are advised to shut down or restrict NetScaler appliances in the interim.
- Risks include unauthorized access, data exfiltration, and service disruption for unpatched systems.
Related Security News
Official MCP Python SDK Flaw Can Let Malicious Servers Steal OAuth Credentials
The maintainers of the official MCP Python SDK disclosed a security vulnerability that could allow a malicious server to trick applications into divulging OAuth credentials. The issue affects the handling of client secrets, authorization codes, and PKCE proof keys when communicating with token endpoints.
CISA Adds Two Citrix NetScaler Vulnerabilities to Known Exploited Catalog
The Cybersecurity and Infrastructure Security Agency (CISA) has added two new vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog based on evidence of active exploitation. CVE-2026-88771 involves improper input validation and CVE-2026-88772 involves improper restriction of operations within the bounds of a memory buffer, both affecting Citrix NetScaler products. The additions trigger remediation requirements under Binding Operational Directive 26-04 for Federal Civilian Executive Branch agencies.
