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Fencer Intel
critical 9.8

CVE-2026-88771 kev in the critical feed json

A remote code execution vulnerability exists due to improper input validation, which can allow an unauthenticated attacker to execute arbitrary commands

published last mo. modified last mo. also EUVD-2026-87958

cvss
9.8
version 3.1, NVD
cisa kev
Exploited
added 2026-09-27
epss
81.9%
EPSS 81.9% chance of exploitation in 30 days, percentile 99.6%
public exploits
1
Metasploit

Summary

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.

Patch / fix

cisa 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.

  • Citrix NetScaler ADC 13.1-64.23, 13.1.37.279 FIPS and NDcPP, 14.1-73.37, 14.1-73.37 FIPS
  • Citrix NetScaler Gateway 13.1-64.23, 14.1-73.37

Is CVE-2026-88771 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Timeline

  1. CISA SSVC: exploitation active
  2. First public exploit (Metasploit exploit/freebsd/http/citrix_netscaler_cve_2026_88771)
  3. Added to CISA KEV
  4. Published
  5. CISA patch deadline

Known exploited

Added
last mo.
Patch by
2026-09-30 (last mo.)
Ransomware
Not known
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.
Vendor, product
Citrix, NetScaler
CISA name
Citrix NetScaler Improper Input Validation Vulnerability

CISA SSVC

Exploitation
Active, exploited in the wild
Automatable
yes
Technical impact
total
Assessed
last mo.

Exploit prediction

81.89% chance of exploitation in the next 30 days, higher than 99.6% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

CVSS scores

assigned by version score vector
CNA 4.0 9.5 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
CNA 4.0 9.5 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
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Citrix NetScaler ADC
  • Citrix NetScaler Gateway

Classification

Weakness
  • CWE-20 Improper Input Validation
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.