CVE-2026-8452

Citrix NetScaler ADC and NetScaler Gateway Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability

Actively exploited (CISA KEV) Critical 9.8 CVSS 3.1

Description

Memory overflow vulnerability NetScaler ADC and NetScaler Gateway leading to unpredictable or erroneous behavior and Denial of Service if the appliance is configured as a Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server

Description as published by the source, in English.

Key facts

Published: 2026-06-30
Last modified: 2026-08-27
Assigned by: 50a63c94-1ea7-4568-8c11-eb79e7c5a2b5
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Scored by: nvd@nist.gov (NVD Primary)
Probability of exploitation: 0.5 % higher than 39 % of all known vulnerabilities
EPSS, next 30 days, model v2026.06.15
Fix available: Not registered in the sources

Actively exploited

CISA added this vulnerability to the Known Exploited Vulnerabilities catalogue on 2026-08-26, with a remediation deadline of 2026-08-29 for US federal agencies.

Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Affected products

Vendor	Product	Versions	Status
Citrix	Netscaler Application Delivery Controller	< 13.1-37.272	Affected
Citrix	Netscaler Application Delivery Controller	14.1-66.68	Affected
Citrix	Netscaler Application Delivery Controller	≥ 13.1, < 13.1-63.18	Affected
Citrix	Netscaler Application Delivery Controller	≥ 14.1, < 14.1-72.61	Affected
Citrix	Netscaler Gateway	≥ 13.1, < 13.1-63.18	Affected
Citrix	Netscaler Gateway	≥ 14.1, < 14.1-72.61	Affected

Weakness type

CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations tha…

References

https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696604 Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-8452 US Government Resource

Related at Berigo

Articles

Nine vulnerabilities entered the exploited catalogue in two days Mentions this CVE 2026-09-01
CISA catalogued three more vulnerabilities on 27 August 2026, a day after six others went in. The three cover ownCloud, the Linux kernel and JFrog Ar…
Citrix reports multiple vulnerabilities in NetScaler ADC and Gateway Mentions this CVE 2026-06-30
Citrix has published a bulletin covering multiple NetScaler ADC and Gateway vulnerabilities, scored 6.9 to 8.8 in CVSSv4 and requiring no authenticat…
Five of the six new KEV entries date from 2015 to 2022 Same product 2026-08-27
CISA has added six vulnerabilities to its Known Exploited Vulnerabilities catalogue. Five were published between 2015 and 2022, and three grant nothi…
Unit 42: Chinese speaking actor ran autonomous attacks with an AI agent Same product 2026-07-31
On 30 July 2026 Unit 42 published a campaign in which a Chinese speaking actor let an AI agent find targets, fetch exploit code and attempt exploitat…

Does this affect you?

A vulnerability matters only if you run the product, in an affected version, somewhere an attacker can reach.

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Sources and freshness

CVE

What it is: A reference number naming one specific vulnerability, for example CVE-2024-9474.
What it tells you: Which vulnerability we are talking about, and in which product.
What it does NOT tell you: Nothing about how serious it is, whether anyone is exploiting it, or whether it concerns you.
Why it matters: Without a shared number, vendor, authority and tooling cannot discuss the same flaw.
Used with the others: The number is the key. NVD, KEV and EPSS all describe the same CVE.

NVD CWE CISA KEV EPSS

How to read this together

No single value should be used on its own. A high CVSS score does not mean a vulnerability is being exploited, and a low one does not mean it is harmless. The four sources answer four different questions.

CVE names the specific vulnerability.
NVD adds severity and technical detail about it.
CWE describes the type of mistake behind it.
CISA KEV shows that it is already being exploited.
EPSS estimates how likely exploitation is soon.

The order that decides what is urgent

Do you actually have the product?
Is the version you run affected?
Is it listed in CISA KEV?
Does it have a high EPSS score?
Is the system reachable from the internet or from others?
How important is the system to the business?
Are there compensating controls already in place?

The first two questions are not about the vulnerability at all. They are about you, and they remove most of the list before you start.

A short example

Fix this week

CVSS 6,5 (medium)

In CISA KEV: yes
EPSS: 94 per cent
A firewall facing the internet

Can be scheduled

CVSS 9,8 (critical)

In CISA KEV: no
EPSS: 0,04 per cent
A test server with no internet access

Sorted by CVSS alone, the one on the right comes first. It is the more serious flaw in theory. But the one on the left is being used against real organisations right now, and it sits where an attacker can reach it. That is the one to fix first.

The critical one still has to be fixed. It just does not have to be fixed today.

This product uses the NVD API but is not endorsed or certified by the NVD. CVE and the CVE logo are registered trademarks of The MITRE Corporation; CVE records are used under the CVE Terms of Use. CWE is a trademark of The MITRE Corporation, used per the CWE Terms of Use. KEV data from CISA (CC0). Exploitation probability from EPSS, a FIRST.org project. Open-source package data from OSV and the GitHub Advisory Database (CC-BY 4.0).

Scores and vectors are shown as published by the sources. The ordering of results is Berigo's own editorial assessment, described on the search page, and is not NVD data. An empty result never means a system is safe.