Critical Citrix NetScaler and Gateway Vulnerabilities Let Remote Attackers Leak Sensitive Information

Home Cyber Security News Critical Citrix NetScaler and Gateway Vulnerabilities Let Remote Attackers Leak Sensitive Information Cloud Software Group has issued a critical security bulletin detailing two newly discovered vulnerabilities affecting customer-managed NetScaler ADC and NetScaler Gateway appliances. These flaws, tracked as CVE-2026-3055 and CVE-2026-4368, could allow remote attackers to leak sensitive information or cause user session mixups. Network administrators and security teams are strongly urged to apply the latest security patches immediately to prevent potential network compromise. Citrix NetScaler and Gateway Vulnerabilities The security bulletin outlines two distinct vulnerabilities affecting different configurations of the NetScaler appliances. The most severe of the two flaws is CVE-2026-3055, an out-of-bounds read vulnerability caused by insufficient input validation. Earning a critical base score of 9.3, this flaw enables remote attackers to trigger a memory overread. An out-of-bounds read allows an attacker to access memory locations beyond a buffer’s intended boundaries, potentially exposing sensitive operational data, credentials, or session tokens. However, exploitation is conditionally restricted. The vulnerability only affects appliances explicitly configured as a Security Assertion Markup Language (SAML) Identity Provider (IdP). Administrators can quickly verify their exposure by checking their NetScaler configuration for the specific string add authentication samlIdPProfile .*. The second vulnerability, CVE-2026-4368, is a race condition flaw that triggers a user session mixup. Session mixups can inadvertently transfer an active session belonging to one user to another, unintentionally exposing sensitive information or granting access. This issue is triggered when the appliance operates as a Gateway (including SSL VPN, ICA Proxy, CVPN, and RDP Proxy) or as an Authentication, Authorization, and Auditing (AAA) virtual server. Configuration files containing add authentication vserver .* or add vpn vserver .* indicate an exposed deployment. These vulnerabilities exclusively impact customer-managed NetScaler ADC and Gateway systems. Cloud environments utilizing Citrix-managed cloud services or Citrix-managed Adaptive Authentication are not at risk, as the vendor has already applied the necessary infrastructure updates. To secure network infrastructure, cybersecurity teams must immediately upgrade affected appliances to the latest supported firmware versions. The flaws were identified during internal security reviews by Cloud Software Group, and there are currently no indicators of active exploitation in the wild. Regardless, the critical nature of the memory overread vulnerability necessitates rapid patching and vigilant monitoring of session integrity. Follow us on Google News, LinkedIn, and X for daily cybersecurity updates. Contact us to feature your stories. RELATED ARTICLESMORE FROM AUTHOR Cyber Security News Fake Cloudflare CAPTCHA Pages Spread Infiniti Stealer Malware on macOS Systems Cyber Security News New Windows Error Reporting Vulnerability Lets Attackers Escalate to Gain SYSTEM Access Cyber Security News ISC Warns of High-Severity Kea DHCP Flaw That Can Crash Services Remotely Top 10 Essential E-Signature Solutions for Cybersecurity in 2026 January 31, 2026 Top 10 Best Data Removal Services In 2026 January 29, 2026 Best VPN Services of 2026: Fast, Secure & Affordable January 26, 2026 Top 10 Best Data Security Companies in 2026 January 23, 2026 Top 15 Best Ethical Hacking Tools – 2026 January 15, 2026