CVE-2026-88771
Citrix NetScaler ADC and NetScaler Gateway contain an improper input validation vulnerability that could allow an unauthenticated attacker to execute arbitrary commands.
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.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X- support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096Vendor Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-88771US Government Resource
- Threat Brief: NetScaler Zero Days CVE-2026-88771 and CVE-2026-88772 Exploited in the Wild (Updated September 30)
Unit 42 is aware of possible 0-day activity against NetScaler devices. Citrix reports CVE-2026-88771, CVE-2026-88772 have been exploited in the wild. The post Threat Brief: NetScaler Zero Days CVE-2026-88771 and CVE-2026-88772 Exploited in the Wild (Updated September 30) appeared first on Unit 42 .
Unit 42 · 25d ago - CISA Adds Two Known Exploited Vulnerabilities to Catalog
CISA has added two new vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog , based on evidence of active exploitation. CVE-2026-88771 Citrix NetScaler Improper Input Validation Vulnerability CVE-2026-88772 Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability These types of vulnerabilities are frequent attack vectors for malicious cyber actors an
CISA Alerts · 28d ago - Critical Zero-Day Vulnerabilities Exploited in Citrix NetScaler ADC, Gateway
Update October 9, 2026 : CISA has updated this Alert to: (1) include CVE-2026-107406; (2) include CVE-2026-88779 following its addition to the KEV Catalog on Oct. 4, 2026; (3) clarify the potential relationship between CVE-2026-88779 and CVE-2026-88771; and (4) emphasize the importance of promptly applying patches for CVE-2026-88771 through CVE-2026-88779 and CVE-2026-107406, as well as reviewing Citrix guidanc
CISA Alerts · 28d ago
Actively exploited. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 26 days
- CVSS
- 9.5 CRITICAL
- EPSS (30-day exploit probability)
- 82.2% · top 1% of all CVEs
- Weakness
- CWE-20
- Attack vector
- Network, remotely reachable
- Preconditions
- No privileges and no user interaction
- 1.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.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
- 4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.