Vulnerability report

Exploitation Attempts Observed Confirmed Confidence In CISA KEV

CVE-2026-88772

ADC Remote Code Execution

Citrix NetScaler / ADC · affected before 14.1-73.37

Watch CVE-2026-88772 Browse KEV feed
Severity
CVSS 9.5 · Critical
Confidence
Confirmed
Exploit status
Exploitation Attempts Observed in the Wild
EPSS
76.6%
First observed
05 Oct 2026
Last observed
06 Nov 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-88772 is an unauthenticated vulnerability affecting Citrix NetScaler ADC, Gateway. Vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway.

Have exploitation attempts been observed?

Yes. Previdian sensors have observed 1,440 exploitation attempts, 4 unique attacker IPs, and 4 countries targeting CVE-2026-88772. First observed Oct 05, 2026; last observed Nov 06, 2026. Listed in CISA KEV. Also reported by third-party sources. Confidence is confirmed.

Who is affected?

Citrix NetScaler / ADC and Gateway, including affected before 14.1-73.37, affected before 13.1-64.23, and affected before 14.1-73.37 FIPS.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

Vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway

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 Remote Code Execution or Denial of Service

Citrix NetScaler Affected
ADC
Before 14.1-73.37 Before 13.1-64.23 Before 14.1-73.37 FIPS Before 13.1.37.279 FIPS and NDcPP
Citrix NetScaler Affected
Gateway
Before 14.1-73.37 Before 13.1-64.23
Published
27 Sep 2026
Exploitation Attempts Reported
27 Sep 2026
Attack vector
Remote
Complexity
High
Privileges
None
User interaction
None

Tags

cisa metasploit_scanner

CVE References

Exploitation evidence

Evidence of exploitation attempts

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploitation Attempts Observed in the Wild

Citrix

Recorded 27 Sep 2026

A trusted third party reported exploitation attempts.

Exploitation Attempts Observed

Previdian sensor

First observed 05 Oct 2026

Previdian sensors observed exploitation attempts targeting this vulnerability.

Proof of concept available

GitHub

Recorded 27 Sep 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
Citrix First 2026-09-27 16:45 UTC
CVE 2026-09-27 20:40 UTC
Tenable Blog 2026-09-27 21:21 UTC
CISA 2026-09-27 21:50 UTC
The Hacker News 2026-09-28 07:30 UTC
CERT Polska 2026-09-28 08:21 UTC
Rapid7 2026-09-28 10:21 UTC
NCSC Alerts and Advisories 2026-09-28 12:20 UTC
Palo Alto Unit42 2026-09-28 15:21 UTC
Qualys ThreatPROTECT 2026-09-28 16:20 UTC
watchTowr 2026-09-29 14:20 UTC
Google Threat Intelligence 2026-09-29 14:21 UTC
Security Affairs 2026-09-30 08:21 UTC
Arctic Wolf 2026-10-02 17:21 UTC
Previdian Sensors 2026-10-05 16:35 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

Previdian Sensor Observations

Previdian sensor observations are exploitation attempts targeting this vulnerability. They do not show that the target was vulnerable or that the attempt succeeded. The cards and chart show volume, unique attackers, and daily activity.

1,440

Attempts observed

4

Unique attacker IPs

4

Attacker countries

CA · NL · TW · US

2

Sensors observed

CVE-2026-88772 exploitation attempts over the last 42 days

Daily events observed by Previdian sensors

Updated 14 Nov 2026

0
120
0
120
0
0
0
0
0
0
0
0
0
0
0
0
240
0
0
0
0
0
0
120
120
240
0
120
0
120
0
120
0
120
0
0
0
0
0
0
0
0
4 Oct 13 Oct 22 Oct 31 Oct 14 Nov

First observed 05 Oct 2026 · Last observed 06 Nov 2026

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Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Attacker IP Indicators

Attacker IP indicators observed · available in Pro and Enterprise.

Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.

Learn about Pro API access

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Metasploit https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/freebsd/http/citrix_netscaler_cve_2026_88771.rb 27 Sep 2026

Risk and context

Severity, weaknesses, and research context

CVSS v4.0

9.5 Critical

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

EPSS

76.6%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Restriction of Operations within the Bounds of a Memory Buffer CWE-119

Recent mention · Citrix

October 2026 Tech Wire

Citrix DaaSNow AvailableCitrix DaaS CloudWhat’s New: Autoscale catalog failover (primary and backup catalogs) — Autoscale starts machines from designated primary catalogs first, switches to backups when capacity runs short, and returns once the primaries recover. Scoped...

Read full advisory

All CVSS Scores

CVSS v4.0 9.5 Critical

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

CVSS v3.1 8.1 High

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

All Mentions

Recent mention · NCSC Alerts and Advisories

Exploitation of vulnerabilities affecting Citrix NetScaler ADC and Citrix NetScaler Gateway

NCSC Alerts and Advisories · 28 Sep 2026

The NCSC is urging UK organisations to promptly mitigate vulnerabilities affecting Citrix NetScaler ADC and Gateway, two of which are being actively exploited.

Recent mention · Rapid7

Zero-Day Exploitation of Citrix NetScaler ADC and Gateway: CVE-2026-88771 and CVE-2026-88772

Rapid7 · 28 Sep 2026

OverviewOn September 27, 2026, Citrix disclosed eight new vulnerabilities affecting NetScaler ADC and NetScaler Gateway, including two critical remote code execution (RCE) vulnerabilities: CVE-2026-88771 and CVE-2026-88772. Both of these RCE vulnerabilities carry a critical CVSSv4 score of 9.5, and both have been confirmed as being actively exploited in the wild as zero-days prior to the vendor disclosure. CVE-2026-88771 affects vulnerable NetScaler deployments in their default configuration, with no additional product features required. The vendor has also indicated that the attack...

Recent mention · TheRegister

Certainties in life: Death, taxes, and critical Citrix vulns under attack

TheRegister · 28 Sep 2026

Sunday NetScaler patch dump fixes trio of critical vulns and five more serious messes

Recent mention · The Hacker News

CISA Says Attackers Are Exploiting Two Critical Citrix NetScaler Flaws Globally

The Hacker News · 28 Sep 2026

Ravie LakshmananSep 28, 2026Vulnerability / Network Security The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Sunday added two critical Citrix NetScaler ADC and Gateway flaws to its Known Exploited Vulnerabilities (KEV) catalog, following reports of active exploitation. The vulnerabilities are listed below - CVE-2026-88771 (CVSS score: 9.5) - An improper input validation vulnerability that could allow an unauthenticated attacker to execute arbitrary commands. CVE-2026-88772 (CVSS score: 9.5) - An improper restriction of operations within the bounds of a memory buffer...

Recent mention · Security Affairs

Citrix Confirmed Two New NetScaler Flaws Exploited as Zero-Day

Security Affairs · 27 Sep 2026

Citrix confirmed two critical NetScaler zero-days were exploited before patches were available, with attackers able to remotely execute code. Citrix confirmed that two critical zero-day vulnerabilities in NetScaler ADC and NetScaler Gateway were exploited before the company released patches. The flaws allow remote code execution, meaning attackers can potentially take control of affected appliances. The […]

Recent mention · NCSC Security Advisories

NCSC-2026-0394 [1.00] [H/H] Kwetsbaarheden verholpen in NetScaler ADC en NetScaler Gateway

NCSC Security Advisories · 27 Sep 2026

Citrix heeft 8 kwetsbaarheden verholpen in NetScaler ADC en NetScaler Gateway. De volgende ondersteunde versies van Citrix NetScaler ADC en Citrix NetScaler Gateway zijn kwetsbaar: - Citrix NetScaler ADC en Citrix NetScaler Gateway 14.1 vóór versie 14.1-73.37 - Citrix NetScaler ADC en Citrix NetScaler Gateway 13.1 vóór versie 13.1-64.23 - Citrix NetScaler ADC FIPS vóór versie 14.1-73.37 FIPS - Citrix NetScaler ADC FIPS en NDcPP vóór versie 13.1-37.279 Secure Private Access Hybrid-implementaties die gebruikmaken van NetScaler-instances zijn ook kwetsbaar voor deze kwetsbaarheden. Deze...

Recent mention · Citrix

Citrix NetScaler ADC and Citrix NetScaler Gateway Security Bulletin for CVE-2026-88771 through CVE-2026-88778

Citrix · 27 Sep 2026

Guidance for customers on newly addressed vulnerabilities and recommended updates As the cybersecurity landscape continues to evolve, organizations across the industry are seeing changes in the pace, scale, and complexity of vulnerability research, discovery, and analysis. AI-assisted research and automation may contribute to this shift by enabling faster identification and validation of certain classes of security issues. Citrix continues to invest in secure development, security testing, coordinated disclosure, and vulnerability response processes. Citrix has released updates for...

Recent mention · CERT Polska

Podatności 0-day w urządzeniach Citrix NetScaler

CERT Polska · 27 Sep 2026

Zespół CERT Polska informuje o dwóch podatnościach 0-day w urządzeniach Citrix NetScaler, które są aktywnie wykorzystywane do ataków.Na podstawie dostępnych informacji należy założyć, że podatności umożliwiają zdalnemu, nieuwierzytelnionemu atakującemu wykonanie dowolnego kodu na urządzeniu. Szczegóły techniczne nie zostały jeszcze ujawnione, a producent nie opublikował aktualizacji bezpieczeństwa.Z uwagi na aktywnie wykorzystywane luki i brak dostępnej poprawki, rekomendujemy odłączenie urządzeń NetScaler od Internetu oraz śledzenie oficjalnych komunikatów producenta.Biuletyny...

Recent mention · Tenable Blog

Frequently asked questions about reported Citrix NetScaler zero-day vulnerabilities

Tenable Blog · 27 Sep 2026

CVE-2026-88771 and CVE-2026-88772, two zero-day vulnerabilities in Citrix NetScaler, have been confirmed as exploited in the wild. Citrix released patches on September 27, 2026.Change logUpdate September 27: Citrix published security bulletin CTX697096, confirming CVE-2026-88771 and CVE-2026-88772 as the two zero-day RCE vulnerabilities and releasing patches. Post updated with CVE IDs, CVSS scores, patch versions, and IoC guidance.Click here to review the change log historyUpdate September 27: Citrix published security bulletin CTX697096, confirming CVE-2026-88771 and CVE-2026-88772 as the...

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

FollowerSeize/CVE-2026-88772-POC

github · Created 2026-09-28 09:58:16 UTC · 0 stars · AI assessment 85%

CVE-2026-88772 - Citrix NetScaler ADC/Gateway DTLS memory overflow (RCE/DoS)

murrez/CVE-2026-88772

github · Created 2026-09-27 20:24:56 UTC · 1 stars · AI assessment 85%

CVE-2026-88772 PoC: Citrix NetScaler ADC/Gateway DTLS memory overflow (RCE/DoS, CVSS 9.5). Fingerprints Gateway, build vs 14.1-73.37 / 13.1-64.23, UDP/443 DTLS probe. CTX697096; active exploitation reported. https://pocbit.org/pocs/cve-2026-88772

watchtowrlabs/watchTowr-vs-Citrix-Netscaler-CVE-2026-88772

github · Created 2026-09-27 18:15:55 UTC · 0 stars · AI assessment 90%

Timeline

From disclosure to observed exploitation attempts

  1. 16:30 UTC

    Indicators of compromise added (4)

    Indicators of compromise recorded

  2. 16:30 UTC

    Observed by Previdian sensors

    Previdian sensors observed exploitation attempts targeting this vulnerability.

  3. 17:21 UTC

    KEV confirmed by Arctic Wolf

    Exploitation attempts reported by an external source

  4. 08:21 UTC

    KEV confirmed by Security Affairs

    Exploitation attempts reported by an external source

  5. 14:21 UTC

    KEV confirmed by Google Threat Intelligence

    Exploitation attempts reported by an external source

  6. 14:20 UTC

    KEV confirmed by watchTowr

    Exploitation attempts reported by an external source

  7. 16:20 UTC

    KEV confirmed by Qualys ThreatPROTECT

    Exploitation attempts reported by an external source

  8. 15:21 UTC

    KEV confirmed by Palo Alto Unit42

    Exploitation attempts reported by an external source

  9. 12:20 UTC

    KEV confirmed by NCSC Alerts and Advisories

    Exploitation attempts reported by an external source

  10. 10:21 UTC

    KEV confirmed by Rapid7

    Exploitation attempts reported by an external source

  11. 08:21 UTC

    KEV confirmed by CERT Polska

    Exploitation attempts reported by an external source

  12. 07:30 UTC

    KEV confirmed by The Hacker News

    Exploitation attempts reported by an external source

  13. 21:50 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  14. 21:21 UTC

    KEV confirmed by Tenable Blog

    Exploitation attempts reported by an external source

  15. 20:40 UTC

    KEV confirmed by CVE

    Exploitation attempts reported by an external source

  16. 18:15 UTC

    Public PoC available

    Public proof-of-concept code published

  17. 16:45 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party report of exploitation attempts

  18. 16:09 UTC

    CVE published

    Vulnerability disclosed publicly

  19. 00:00 UTC

    Metasploit module available

    Exploit module available

  20. 07:14 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-88772

Sample API response 
{
  "cve_id": "CVE-2026-88772",
  "confidence": "Confirmed",
  "cvss_score": 9.5,
  "cvss_estimated": false,
  "epss_score": 0.76566,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 1440, "sensors": 2 }
}