CVE-2026-88771
citrix netscaler application delivery controller
Summary
CVE-2026-88771: Improper input validation vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway. This issue affects ADC: b
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.
Published 2026-09-27 · first seen here 2026-10-10
CISA required action (due 2026-09-30): 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.
Analysis & write-ups
- Threat Brief: NetScaler Zero Days CVE-2026-88771 and CVE-2026-88772 Exploited in the Wild (Updated September 30) · Unit 42
- Zero-Day Exploitation of Citrix NetScaler ADC and Gateway: CVE-2026-88771 and CVE-2026-88772 · Rapid7
- Oh Look, The Foot Gun Went Off Again (Citrix NetScaler PreAuth Command Injection CVE-2026-88771) · watchTowr Labs
- Citrix NetScaler vulnerabilities (CVE-2026-88771, CVE-2026-88772) in active exploitation · Sophos X-Ops
- Defending Against Active Exploitation of Citrix NetScaler ADC and Gateway Appliances · Google Threat Intelligence
- Here We Go Again (Citrix NetScaler DTLS Preauth Memory Overflow CVE-2026-88772) · watchTowr Labs
Exploit availability
Public exploit code lowers the bar for attackers, so prioritise patching and hunting. These repositories are unverified. Fake PoCs that contain malware are common, so never run them outside an isolated lab.
- watchtowrlabs/watchTowr-vs-Citrix-Netscaler-CVE-2026-88771 · ★23 · created 2026-09-27
- ThomasPoppelgaard/netscaler-ctx697096-checker · ★18 · created 2026-09-28
- technion/netscaler_scanner · ★1 · created 2026-09-28
- grupooruss/netscaler-defensive-checker · ★1 · created 2026-10-08
- EXEcution-py/CVE-2026-88771-POC · ★0 · created 2026-09-28
- +7 more
Hunt & detect
Threat hunt brief, Sigma rule and Splunk / Sentinel / CrowdStrike queries are not available for this item yet.
News & advisories
- 5th October – Threat Intelligence Report · Check Point Research
References
- NVD entry
- CISA KEV
- https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-88771
- https://community.citrix.com/techzone-blogs/110_security-updates/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve-2026-88771-through-cve-2026-88778
- https://support.citrix.com/external/article/CTX694799/steps-to-take-if-netscaler-adc-is-suspec.html
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk