Citrix NetScaler
CVE-2026-88772
Vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway. This issue affects ADC: before 14.1-73.37, before 13.1-64.23, before 14.1-73.37 FIPS, and before 13.1.37.279 FIPS and NDcPP; Gateway: before 14.1-73.37 and before 13.1-64.23 leading to Remote Code Execution or Denial of Service
What this means for your business
- It affects Citrix NetScaler. It matters if your company, or a supplier that handles your data, runs it.
- Attackers are already using it. CISA added it to its list of flaws used in real attacks on 27 September 2026.
What to do
- 1Check whether your company or your suppliers run Citrix NetScaler.
- 2If you do, follow CISA's required action below. No patch reference has been published yet.
- 3Treat it as urgent. US federal agencies must fix it by 30 September 2026. That deadline does not apply to private companies, but it shows how seriously CISA takes it.
- 4Because attackers have used it, check the affected systems for signs of a break-in, not only for the update.
Fastnexa security experts
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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.
CISA’s wording, unedited. The notes it mentions are in CISA’s catalogue entry.
Scoring
- CVSS
- Not yet scored
- CVSS v4
- 9.5
- Weakness
- CWE-119
- Assigned by
- 50a63c94-1ea7-4568-8c11-eb79e7c5a2b5
Dates
- Published
- 2026-09-27
- Last modified
- 2026-09-28
- Added to KEV
- 2026-09-27
- Remediation due
- 2026-09-30
- Sources
- CISA KEV, NVD
Coverage
- AL26-024 - Critical vulnerabilities affecting Citrix NetScaler ADC and NetScaler Gateway – CVE-2026-88771 and CVE-2026-88772Canadian Centre for Cyber Security · 2026-09-27
- Citrix confirms two NetScaler RCE zero-days exploited in attacksBleepingComputer · 2026-09-27
References
- https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096&articleTitle=Citrix_NetScaler_ADC_and_Citrix_NetScaler_Gateway_Security_Bulletin_for_CVE_2026_88771_CVE_2026_88772_CVE_2026_88773_CVE_2026_88774_CVE_2026_88775_CVE_2026_88776_CVE_2026_88777_and_CVE_2026_88778
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-88772