---
id: "CVE-2026-120866"
page: "https://infrastack.ai/live/CVE-2026-120866"
kind: "vulnerability"
aliases: ["CVE-2026-120866"]
title: "Citrix NetScaler: BGP routing memory overflow enables denial of service"
severity: "high"
cvss: 7.7
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "NetScaler ADC and Gateway 14.1", "fixed": ["14.1-73.57"], "affected": "< 14.1-73.57", "ecosystem": "vendor"}, {"name": "NetScaler ADC and Gateway 13.1", "fixed": ["13.1-64.39"], "affected": "< 13.1-64.39", "ecosystem": "vendor"}, {"name": "NetScaler ADC 14.1-FIPS", "fixed": ["14.1-73.58 FIPS"], "affected": "< 14.1-73.58", "ecosystem": "vendor"}, {"name": "NetScaler ADC 13.1-FIPS and 13.1-NDcPP", "fixed": ["13.1-37.293"], "affected": "< 13.1-37.293", "ecosystem": "vendor"}]
ecosystems: []
tags: ["adc", "bgp", "citrix", "gateway", "infrastructure", "load-balancer", "netscaler", "netscaler-gateway", "self-hosted"]
not_affected_if: ["no-bgp-dynamic-routing", "no-bgp-neighbor-configured", "tcp-md5-authentication"]
published_at: "2026-11-13T09:17:34+00:00"
first_seen_at: "2026-11-13T09:49:53+00:00"
updated_at: "2026-11-13T09:53:45+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-120866", "first_seen_at": "2026-11-13T09:49:53+00:00"}, {"source": "analyst", "url": "https://support.citrix.com/external/article/CTX697305", "first_seen_at": "2026-11-13T09:53:45+00:00", "cites": ["https://support.citrix.com/external/article/CTX697305", "https://nvd.nist.gov/vuln/detail/CVE-2026-120866", "https://support.citrix.com/external/article/CTX697305"]}]
exploit_sources: []
---

# Citrix NetScaler: BGP routing memory overflow enables denial of service

Link for people: https://infrastack.ai/live/CVE-2026-120866 (this .md is for agents)

A memory overflow in the BGP dynamic routing feature of Citrix NetScaler ADC and NetScaler Gateway can cause unpredictable behavior or a denial of service. The sources do not state that an attacker can run code or read data.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:NetScaler ADC and Gateway 14.1 affected < 14.1-73.57 fixed 14.1-73.57
- vendor:NetScaler ADC and Gateway 13.1 affected < 13.1-64.39 fixed 13.1-64.39
- vendor:NetScaler ADC 14.1-FIPS affected < 14.1-73.58 fixed 14.1-73.58 FIPS
- vendor:NetScaler ADC 13.1-FIPS and 13.1-NDcPP affected < 13.1-37.293 fixed 13.1-37.293

## How to check

On the appliance run 'show ns feature' (BGP must be enabled) and 'show router dynamicRouting' (look for 'router bgp <ASN>' with at least one 'neighbor <IP> remote-as <ASN>'). If BGP is off or no neighbor is configured, Citrix says the appliance is not vulnerable. Also check that each neighbor has TCP-MD5 authentication; the bulletin gives no command for that. Then compare 'show version' with the fixed builds. Also check Secure Private Access Hybrid deployments that use NetScaler instances; the bulletin says they must be upgraded.

## Fix

Upgrade to NetScaler ADC/Gateway 14.1-73.57 or later, 13.1-64.39 or later; ADC 14.1-FIPS 14.1-73.58 FIPS or later; 13.1-FIPS and 13.1-NDcPP 13.1-37.293 or later. Bulletin lists no mitigation or workaround.

## Timeline

- 2026-11-13T09:49:53+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-120866
- 2026-11-13T09:53:45+00:00 analyst https://support.citrix.com/external/article/CTX697305 — Read Citrix bulletin CTX697305 (via WebFetch; web-cli get truncated before the precondition steps). Fixed builds, BGP precondition and check commands taken from it. No exploitation or PoC found; X not searched.

## Documents

- [advisory] Citrix NetScaler ADC and Gateway Security Bulletin CTX697305 https://support.citrix.com/external/article/CTX697305
- [describes] NVD CVE-2026-120866 https://nvd.nist.gov/vuln/detail/CVE-2026-120866
- [fix] Citrix NetScaler ADC and Gateway Security Bulletin CTX697305 https://support.citrix.com/external/article/CTX697305

## From the sources

Memory overflow / improper handling in BGP dynamic routing can lead to unpredictable or erroneous behavior or Denial of Service in Citrix NetScaler ADC and Citrix NetScaler Gateway.

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_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_