Main Vulnerability Database Vulnerabilities #VU144333

Buffer overflow in Citrix Netscaler ADC and Citrix NetScaler Gateway - CVE-2026-19489

Published: August 19, 2026

Vulnerability identifier: #VU144333

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-19489

CWE-ID: CWE-119

Exploitation vector: Remote access

Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper restriction of operations within the bounds of a memory buffer in the SIP ALG processing component when handling SIP ALG traffic on a Large Scale NAT group configuration. A remote attacker can send crafted network traffic to cause a denial of service.

Only appliances with SIP ALG enabled on a Large Scale NAT group configuration are vulnerable.

Affected software

Citrix Netscaler ADC
Citrix NetScaler Gateway

How to mitigate CVE-2026-19489

Install security update from vendor's website.

Citrix Netscaler ADC - addressed in versions 13.1-63.21, 14.1-73.32
Citrix NetScaler Gateway - addressed in versions 13.1-63.21, 14.1-73.32

External References

Related Security Bulletins