CVE-2026-88771
Critical9.5CISA KEV — exploited in the wildImproper 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
- 9.5v4.0
- EPSS (exploit probability)
- 1.1%65th pct
- CISA KEV
- Listed
EPSS trendFIRST daily scores, last 90 days
Daily values
| Score date | EPSS | Percentile |
|---|---|---|
| 2026-10-20 | 1.1% | 64.7% |
| 2026-10-19 | 1.1% | 64.7% |
| 2026-10-18 | 1.1% | 64.6% |
| 2026-10-16 | 1.1% | 64.6% |
| 2026-10-15 | 1.1% | 64.6% |
| 2026-10-14 | 1.1% | 64.5% |
| 2026-10-13 | 1.1% | 64.3% |
| 2026-10-12 | 1.1% | 64.3% |
| 2026-10-11 | 1.1% | 64.3% |
| 2026-10-10 | 1.1% | 64.2% |
| 2026-10-09 | 1.1% | 64.2% |
| 2026-10-08 | 1.1% | 64.2% |
| 2026-10-07 | 1.1% | 64.2% |
| 2026-10-06 | 1.1% | 64.1% |
| 2026-10-05 | 1.1% | 64.0% |
| 2026-10-04 | 1.1% | 63.5% |
| 2026-10-03 | 1.1% | 63.5% |
| 2026-10-02 | 1.1% | 63.4% |
| 2026-10-01 | 1.1% | 63.4% |
| 2026-09-30 | 1.1% | 63.3% |
| 2026-09-29 | 1.1% | 63.3% |
CISA KEV entrycatalogue 2026.10.20
- Date added
- 2026-09-27
- Federal due date
- 2026-09-30
- Known ransomware use
- 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.
Verbatim from the CISA KEV catalogue (CISA KEV, fetched 2026-10-21 07:34 UTC). The due date applies to US federal agencies under BOD 22-01.
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
Affected products
- citrix netscaler application delivery controller
- citrix netscaler gateway