CVEs / CVE-2026-88771
CVE-2026-88771: Citrix NetScaler Improper Input Validation Vulnerability
- Known exploited in the CISA KEV catalog since 27 Sep 2026
- critical 9.8 CVSS 3.1 (NVD)
- EPSS 82.1% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Citrix NetScaler ADC and NetScaler Gateway contain an improper input validation vulnerability that could allow an unauthenticated attacker to execute arbitrary commands.
Description
Improper input validation 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 an unauthenticated attacker to execute arbitrary commands.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Citrix NetScaler ADC | before 14.1-73.37 | 14.1-73.37 |
| Citrix NetScaler ADC | before 13.1-64.23 | 13.1-64.23 |
| Citrix NetScaler ADC | before 14.1-73.37 FIPS | 14.1-73.37 FIPS |
| Citrix NetScaler ADC | before 13.1.37.279 FIPS and NDcPP | 13.1.37.279 FIPS and NDcPP |
| Citrix NetScaler Gateway | before 14.1-73.37 | 14.1-73.37 |
| Citrix NetScaler Gateway | before 13.1-64.23 | 13.1-64.23 |
Exploitation
| In CISA KEV since | 27 Sep 2026 |
|---|---|
| Due date for US federal agencies | 30 Sep 2026 |
| Used in ransomware campaigns | Unknown |
| 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. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-20 |
References
- CVE-2026-88771 on NVD
- CVE-2026-88771 in the CISA KEV catalog
- https://community.citrix.com/techzone-blogs/110_security-updates/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve-2026-88771-through-cve-2026-88778 (cited by CISA)
- https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096 (cited by CISA)
- https://support.citrix.com/external/article/CTX694799/steps-to-take-if-netscaler-adc-is-suspec.html (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (cited by CISA)
- https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096 Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-88771 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.