CVE-2026-3055: critical vulnerability in NetScaler ADC
Insufficient input validation leading to memory overread
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
Patch now. It under exploitation confirmed by CISA, has an official Brazilian government alert and has a working public exploit.
Brazil's federal government published an alert, recommendation or bulletin that cites this vulnerability.
- CTIR Gov · ALERTA 22/2026Vulnerabilidade crítica no NetScalerread on gov.br ↗
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
NetScaler ADC and NetScaler Gateway have a flaw in how they validate user input when acting as a SAML identity provider. An attacker can send specially crafted requests that cause the system to read beyond intended memory boundaries, potentially exposing sensitive data.
Insufficient input validation in the SAML IDP implementation allows an unauthenticated or low-privileged attacker to trigger an out-of-bounds memory read via malformed SAML requests. The vulnerability enables information disclosure of adjacent memory contents without requiring code execution, with a CVSS score of 9.3 indicating critical severity.
The full analysis of this CVE is available in Portuguese →
In the same product, most dangerous first.