Zero-Day Exploitation of Citrix NetScaler ADC and Gateway: CVE-2026-88771 and CVE-2026-88772
Attackers are exploiting critical Citrix NetScaler zero-days CVE-2026-88771 and CVE-2026-88772 for unauthenticated remote code execution.
Memory Overflow in Citrix NetScaler ADC and Gateway
CVE-2026-88775 is a memory overflow in Citrix NetScaler ADC and Citrix NetScaler Gateway. CVSS 4.0 rates it 8.8 (high): it is reachable over the network with low complexity and requires no privileges and no user interaction. Successful exploitation can cause unpredictable or erroneous behavior or denial of service, with low confidentiality and integrity impact and high availability impact on the vulnerable appliance and no documented impact on subsequent systems. It affects ADC builds 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, and Gateway builds before 14.1-73.37 and before 13.1-64.23. The CVE is not in CISA KEV and no public proof-of-concept is known; a related headline describes actively exploited NetScaler zero-day remote-code-execution issues, but that claim is not confirmed for this CVE in the supplied record.
What to do: Upgrade NetScaler ADC to 14.1-73.37 or later, 13.1-64.23 or later, 14.1-73.37 FIPS or later, or 13.1.37.279 FIPS/NDcPP or later, and NetScaler Gateway to 14.1-73.37 or later or 13.1-64.23 or later. Until patched, restrict exposure of ADC and Gateway services to trusted networks and watch for crashes, restarts, or other availability failures. This CVE is not in CISA KEV and has no known public PoC; still treat unpatched internet-facing appliances as high priority.
| Product | Affected |
|---|---|
| Citrix NetScaler 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 |
| Citrix NetScaler Gateway | before 14.1-73.37 and before 13.1-64.23 |
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Memory overflow 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 Memory overflow vulnerability leading to unpredictable or erroneous behavior or Denial of Service
Attackers are exploiting critical Citrix NetScaler zero-days CVE-2026-88771 and CVE-2026-88772 for unauthenticated remote code execution.
Citrix confirms two critical NetScaler zero-days, CVE-2026-88771 and CVE-2026-88772, are actively exploited for remote code execution.
Citrix reports NetScaler ADC and Gateway zero-days CVE-2026-88771/88772 (CVSS 9.5) exploited in the wild, with over 50,000 exposed instances.
Citrix and CISA warn NetScaler ADC and Gateway zero-days CVE-2026-88771 and CVE-2026-88772 are under active attack.
Citrix patched two actively exploited critical NetScaler zero-days enabling unauthenticated remote code execution.
Citrix confirms attackers are exploiting two critical unauthenticated NetScaler RCE zero-days, CVE-2026-88771 and CVE-2026-88772.
Two critical Citrix NetScaler zero-days, CVE-2026-88771 and CVE-2026-88772, are exploited for remote code execution.
watchTowr details CVE-2026-88771, a pre-auth command injection in Citrix NetScaler ADC/Gateway patched in bulletin CTX697096 and already exploited as a zero-day.
watchTowr dissects CVE-2026-88772, an in-the-wild-exploited pre-auth DTLS memory overflow in Citrix NetScaler enabling RCE, one of eight fixed flaws.
CISA says exploited Citrix NetScaler zero-days CVE-2026-88771 and CVE-2026-88772 need urgent patching.
The UK NCSC urged immediate patching after two critical Citrix NetScaler zero-days were exploited for unauthenticated remote code execution.
NCSC warns exploited Citrix NetScaler flaws CVE-2026-88771 and CVE-2026-88772 allow remote compromise.
CERT-EU warns two critical Citrix NetScaler RCE flaws are exploited in the wild and urges immediate patching.
CISA added Citrix NetScaler ADC/Gateway flaws CVE-2026-88771 and CVE-2026-88772 to the KEV catalog; Canadian Cyber Centre urges immediate patching.
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