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Important Security Issue Found in Citrix NetScaler Devices

A serious security flaw has been found in Citrix NetScaler ADC and Gateway devices that could cause them to stop working properly or be taken offline. This matters because these devices help manage internet traffic and remote access, so if they fail, it could disrupt your business operations.

30 September 2026

Reference: CVE-2026-88776

1. What is being reported?

Researchers have discovered a memory overflow problem in certain versions of Citrix NetScaler ADC and Gateway products. This flaw can cause the devices to behave unpredictably or crash, potentially leading to denial of service. Some attackers may already be exploiting this issue.

2. What this means in plain English

If your organisation uses these Citrix devices, this vulnerability could allow attackers to disrupt your network services, making it difficult or impossible for staff to access systems remotely or for customers to reach your online services.

3. Could this affect a small business?

Small businesses or charities using Citrix NetScaler ADC or Gateway devices in the affected versions could be at risk. If you do not use these Citrix products, this vulnerability does not affect you.

4. What to do now

  • Check if your organisation uses Citrix NetScaler ADC or Gateway devices.
  • Ask your IT provider whether your devices are running affected versions.
  • If affected, apply updates or patches provided by Citrix as soon as possible.
  • Monitor your systems for unusual behaviour and report any issues to your IT support.

5. Ask your IT provider

Can you confirm if our Citrix NetScaler ADC or Gateway devices are affected by CVE-2026-88776, and have the necessary patches been applied to protect against this vulnerability?

6. Bottom line

If you use Citrix NetScaler devices, act quickly to update them and avoid potential service disruptions.

Information based on CISA KEV, NVD, and reputable security reports.

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