Citrix NetScaler ADC and Gateway Out-of-Bounds Read Vulnerability

Critical Threat Advisory: This vulnerability is documented in active Ransomware campaigns. Immediate remediation required.

Technical Severity

CVSS v3.1 Metrics

HIGH

7.5 / 10

Minimal Risk Critical

Vector Specification

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Exploitation Likelihood

EPSS Prediction

69.81 %

Predictive Probability

Percentile Rank

98.7 th

Documented as more likely to be exploited than 98.7% of known CVEs.

Detection Date

Jul 10, 2025

Remediation Due

Jul 11, 2025

CISA Catalog Active

Threat Analysis

Citrix NetScaler ADC and Gateway contain an out-of-bounds read vulnerability due to insufficient input validation. This vulnerability can lead to memory overread when the NetScaler is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server.

Remediation Directive

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

External Intelligence

https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX693420

NVD

National Vulnerability Database

https://nvd.nist.gov/vuln/detail/CVE-2025-5777