Full Report
Multiple Vulnerabilities have been discovered in NetScaler ADC and NetScaler Gateway, the most severe of which could allow for memory overread.NetScaler ADC is a networking product that functions as an Application Delivery Controller (ADC), a tool that optimizes, secures, and ensures the reliable availability of applications for businesses.NetScaler Gateway is a secure remote access solution that provides users with single sign-on (SSO) to applications and resources from any device, anywhere.Successful exploitation of these vulnerabilities could lead to memory overread of potentially sensitive data from the appliance memory.
Analysis Summary
# Vulnerability: Multiple Memory Overread Flaws in NetScaler ADC and Gateway
## CVE Details
- **CVE ID:** CVE-2026-3055, CVE-2026-4368
- **CVSS Score:** Not explicitly listed (Assessed as **High** risk by MS-ISAC)
- **CWE:** CWE-125 (Out-of-bounds Read), CWE-362 (Race Condition)
## Affected Systems
- **Products:** NetScaler ADC and NetScaler Gateway
- **Versions:**
- Versions 14.1 prior to 14.1-66.59
- Versions 13.1 prior to 13.1-62.23
- NetScaler ADC 13.1-FIPS and 13.1-NDcPP prior to 13.1-37.262
- **Configurations:**
- **CVE-2026-3055:** Requires the appliance to be configured as a SAML Identity Provider (IdP).
- **CVE-2026-4368:** Affects appliances configured as a Gateway (SSL VPN, ICA Proxy, CVPN, or RDP Proxy) or as an AAA virtual server.
## Vulnerability Description
The primary flaw (CVE-2026-3055) is an out-of-bounds memory read caused by insufficient input validation. This allows an attacker to read sensitive data residing in the appliance's memory. A secondary vulnerability (CVE-2026-4368) involves a race condition. High-severity exploitation of these flaws could allow an attacker to harvest credentials from memory, which may subsequently facilitate Remote Code Execution (RCE).
## Exploitation
- **Status:** Not currently reported as exploited in the wild; No PoC available.
- **Complexity:** Medium (Requires specific configurations like SAML IdP).
- **Attack Vector:** Network (Public-facing applications).
## Impact
- **Confidentiality:** High (Sensitive data and credentials can be read from memory).
- **Integrity:** High (Potential path to RCE).
- **Availability:** Low (Primary impact is data exposure).
## Remediation
### Patches
Citrix has released the following updated versions to address these vulnerabilities:
- NetScaler ADC / Gateway 14.1-66.59 or later
- NetScaler ADC / Gateway 13.1-62.23 or later
- NetScaler ADC 13.1-FIPS / 13.1-NDcPP 13.1-37.262 or later
### Workarounds
No specific configuration workarounds were provided. Organizations must update software to the patched versions to mitigate the risk.
## Detection
- **Indicators of Compromise:** Monitor for unusual access patterns to SAML IdP endpoints or AAA virtual servers.
- **Detection methods and tools:** Perform authenticated vulnerability scans using SCAP-compliant tools and conduct periodic external penetration testing to verify the security posture of netscaler instances.
## References
- **Vendor Advisory:** hXXps://support[.]citrix[.]com/support-home/kbsearch/article?articleNumber=CTX696300
- **CVE-2026-3055:** hXXps://www[.]cve[.]org/CVERecord?id=CVE-2026-3055
- **CVE-2026-4368:** hXXps://www[.]cve[.]org/CVERecord?id=CVE-2026-4368