# CVE-2026-111340: Citrix NetScaler memory overflow in KBA authentication

Source: https://junglewise.ai/threats/cve-2026-111340-memory-overflow-in-kba-knowledge-based-authentication-can-lead  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-13. Updated: 2026-11-13  
License: CC BY 4.0 with a link back

CVE-2026-111340 · Severity: info · Published 2026-11-13

Citrix NetScaler ADC and Gateway are access control appliances that authenticate users before granting network access. A memory overflow vulnerability in the knowledge-based authentication (KBA) feature can cause the system to behave unpredictably or stop responding to requests. An attacker could exploit this to disrupt access for legitimate users or trigger unexpected system behavior.

Technologies: [Citrix NetScaler ADC](https://junglewise.ai/threats/technologies/netscaler-adc), [Citrix NetScaler Gateway](https://junglewise.ai/threats/technologies/gateway). Vendors: [Citrix](https://junglewise.ai/threats/vendors/citrix).

## Quick answers

**Is CVE-2026-111340 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-111340 being exploited in the wild.

**How severe is CVE-2026-111340?** Informational severity, published 13 November 2026.

**Which products and versions are affected?** Citrix NetScaler ADC; Citrix NetScaler Gateway.

**Is there a fix for CVE-2026-111340?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-111340 attacked?** It is in a network appliance.

**Am I affected by CVE-2026-111340?** Check whether you run Citrix NetScaler ADC or Citrix NetScaler Gateway. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A memory overflow exists in the KBA (knowledge-based authentication) component of Citrix NetScaler ADC and NetScaler Gateway. The vulnerability can lead to unpredictable behavior or denial of service; the precise attack vector and preconditions are not detailed in the available advisory text.

## Affected products

- Citrix NetScaler ADC
- Citrix NetScaler Gateway

## References

- [https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697305](https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697305)

## Related threats

- [Citrix NetScaler ADC memory overflow in LDAP authentication](https://junglewise.ai/threats/cve-2026-111342-memory-overflow-in-ldap-authentication-can-lead-to-unpredictable)
- [Citrix NetScaler memory overflow in client-certificate authentication](https://junglewise.ai/threats/cve-2026-111341-memory-overflow-in-client-certificate-authentication-can-lead-to)
- [Citrix NetScaler ADC memory overflow in Email OTP authentication](https://junglewise.ai/threats/cve-2026-107415-memory-overflow-in-email-otp-authentication-can-lead-to)
- [Citrix NetScaler ADC memory overflow in WebAuth authentication](https://junglewise.ai/threats/cve-2026-107414-memory-overflow-in-webauth-authentication-can-lead-to)
- [Citrix NetScaler ADC and Gateway memory overflow in SAML authentication](https://junglewise.ai/threats/cve-2026-107413-memory-overflow-in-saml-authentication-can-lead-to-unpredictable)