Citrix NetScaler ADC/NetScaler Gateway Application Firewall buffer overflow

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.5$5k-$25k0.43+

Summaryinfo

A vulnerability was found in Citrix NetScaler ADC and NetScaler Gateway and classified as critical. Impacted is an unknown function of the component Application Firewall. The manipulation results in buffer overflow. This vulnerability is known as CVE-2026-111339. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability was found in Citrix NetScaler ADC and NetScaler Gateway (the affected version is unknown). It has been classified as critical. Affected is an unknown code of the component Application Firewall. The manipulation with an unknown input leads to a buffer overflow vulnerability. CWE is classifying the issue as CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer. This is going to have an impact on integrity, and availability. CVE summarizes:

Memory overflow in Application Firewall data decompression/inspection can lead to unpredictable or erroneous behavior or Denial of Service in Citrix NetScaler ADC and Citrix NetScaler Gateway.

The advisory is available at support.citrix.com. This vulnerability is traded as CVE-2026-111339 since 10/15/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 11/13/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.5

VulDB Base Score: 6.5
VulDB Temp Score: 6.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Buffer overflow
CWE: CWE-120 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

10/15/2026 CVE reserved
11/13/2026 +29 days Advisory disclosed
11/13/2026 +0 days VulDB entry created
11/13/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: citrix.com

Advisory: support.citrix.com
Status: Not defined

CNA: NetScaler
CVE: CVE-2026-111339 (🔒)

GCVE (CVE): GCVE-0-2026-111339
GCVE (VulDB): GCVE-100-436650

Entryinfo

Created: 11/13/2026 09:08
Changes: 11/13/2026 09:08 (64)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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