Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2026-3055 is a critical-severity Out-of-bounds Read (CWE-125) vulnerability in Citrix Netscaler Application Delivery Controller. Its CVSS base score is 9.3 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 0.3% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-3055 is an out-of-bounds memory read (CWE-125) caused by insufficient input validation in Citrix NetScaler ADC and NetScaler Gateway when those appliances are configured as SAML identity providers. The flaw carries a CVSS 4.0 score of 9.3 and affects the SAML assertion handling path, allowing an unauthenticated remote attacker to read memory contents beyond intended boundaries.
An attacker who can reach the SAML IDP endpoint can supply a crafted request that triggers the overread. Successful exploitation yields disclosure of sensitive memory regions, which may contain session tokens, cryptographic material, or other data that can be leveraged to escalate to full compromise of the affected appliance.
Citrix security bulletin CTX696300 describes the affected versions and provides patched builds; administrators are advised to apply the vendor updates or implement the recommended configuration mitigations. The vulnerability is also listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild.
The EPSS score has remained at its observed peak of 0.8992 since disclosure, indicating sustained exploitation interest.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-14546
- 🇬🇧 UK NCSC: Vulnerabilities affecting Citrix NetScaler ADC and Citrix NetScaler Gateway
Vulnerability Data
Insufficient input validation in NetScaler ADC and NetScaler Gateway when configured as a SAML IDP leading to memory overread
- CWE(s)
- KEV Date Added
- 30 March 2026
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation directly finds out-of-bounds read flaws through static analysis, fuzzing, and dynamic bounds checks.
Secure engineering principles require bounds checking and memory-safe constructs that stop out-of-bounds reads from being introduced.
Process isolation confines the effects of an out-of-bounds read to the compromised process.
Input validation rejects malformed indices or lengths that would otherwise cause reads outside buffer bounds.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure-development practices such as bounds checking and memory-safe languages directly prevent out-of-bounds reads.
Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.
Routine patching replaces vulnerable code containing out-of-bounds read flaws.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development and acceptance includes fuzzing and static analysis that detect out-of-bounds read defects before release.
Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.
Secure development life cycle mandates input validation and bounds checking that directly prevent out-of-bounds reads.
Application security requirements include explicit bounds and memory-safety specifications that mitigate buffer over-reads.
Secure system architecture and engineering principles require memory-safe design patterns and runtime protections against out-of-bounds access.
Secure coding standards explicitly forbid unsafe pointer arithmetic and mandate bounds-checked reads, eliminating CWE-125.