CVE-2026-88779: Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability

CVE-2026-88779 · Severity: critical · CVSS 7.5 · Exploited in the wild · Published 2026-10-04

Citrix NetScaler, a network appliance that manages traffic and security for enterprise applications, contains a memory buffer vulnerability that allows attackers to overflow bounds and gain control of the device. CISA has added this vulnerability to its Known Exploited Vulnerabilities catalog, indicating active exploitation in the wild. Federal agencies and other organizations must prioritize patching this flaw to prevent unauthorized access and system compromise.

Technologies: Citrix NetScaler. Vendors: Citrix.

Quick answers

Is CVE-2026-88779 exploited in the wild?
Yes. CVE-2026-88779 is known to be exploited in the wild, first recorded on 4 October 2026. Treat it as urgent.
How severe is CVE-2026-88779?
Critical severity, with a CVSS score of 7.5, published 4 October 2026.
Which products and versions are affected?
Citrix NetScaler.
Is there a fix for CVE-2026-88779?
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-2026-88779 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-88779?
Check whether you run Citrix NetScaler. 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 buffer boundary violation in Citrix NetScaler permits an attacker to write beyond allocated buffer limits, typically enabling arbitrary code execution or complete system takeover. The vulnerability likely requires network access or local interaction; once exploited, an attacker gains full control of the appliance. CISA has designated this as a known exploited vulnerability requiring immediate remediation.

Affected products

  • Citrix NetScaler

Timeline

  • 2026-10-04: kev added: Added to CISA Known Exploited Vulnerabilities Catalog

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