CVE-2023-4966

highpriority · act · 90OT risk · criticalKEV · exploitedEPSS 1.000 · 100 %ileexploit · functionalDEEURUUS

grimoire priorityP0 · Act now

Exploitable?

Yes · in the wild

CISA KEV · 15 exploits · functional

Likely / severe?

100.0% (100th) EPSS

CVSS 7.5 · high

Is it mine?

23 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

added 2023-10-18remediate by 2023-11-08

required action Apply mitigations and kill all active and persistent sessions per vendor instructions [https://www.netscaler.com/blog/news/cve-2023-4966-critical-security-update-now-available-for-netscaler-adc-and-netscaler-gateway/] OR discontinue use of the product if mitigations are unavailable.

EPSS · scored 2026-10-26

Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability

Sensitive information disclosure in NetScaler ADC and NetScaler Gateway when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA  virtual server.

cvss

Technical severity, 0–10. One row per scoring source.

9.4

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.5–9.4

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.19.4criticalAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Lsecondary · FSTEC (BDU) RU

v3.19.4criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Lsecondary · ENISA EU

v3.19.4criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Lsecondary · secure@citrix.comexploitability 3.9 · impact 5.5

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:Hsecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: active · Automatable: yes · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-119USCWE-119US

ATT&CK techniques

ATT&CK techniques this enables or maps to.

exploits (15)

Public proof-of-concept and weaponised exploit code.

auxiliary/scanner/http/citrix_bleed_cve_2023_4966Citrix ADC (NetScaler) Bleed Scannerfunctional · metasploit
0xKayala/CVE-2023-4966CVE-2023-4966 - NetScaler ADC and NetScaler Gateway Memory Leak ExploitPoC · poc_in_github
Chocapikk/CVE-2023-4966Sensitive information disclosure in NetScaler ADC and NetScaler Gateway when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server. PoC · poc_in_github
IceBreakerCode/CVE-2023-4966IceBreakerCode/CVE-2023-4966PoC · poc_in_github
LucasOneZ/CVE-2023-4966LucasOneZ/CVE-2023-4966PoC · poc_in_github
RevoltSecurities/CVE-2023-4966An Exploitation script developed to exploit the CVE-2023-4966 bleed citrix information disclosure vulnerabilityPoC · poc_in_github

affected products (23)

Products and version ranges known to be affected.

Citrix NetScaler ADC12.1-FIPS → 55.300enisa_euvdEU
Citrix NetScaler ADC12.1-NDcPP → 55.300enisa_euvdEU
Citrix NetScaler ADC13.0 → 92.19enisa_euvdEU
Citrix NetScaler ADC13.1 → 49.15enisa_euvdEU
Citrix NetScaler ADC13.1-FIPS → 37.164enisa_euvdEU
Citrix NetScaler ADC14.1 → 8.50enisa_euvdEU
Citrix NetScaler Gateway13.0 → 92.19enisa_euvdEU
Citrix NetScaler Gateway13.1 → 49.15enisa_euvdEU
Citrix NetScaler Gateway14.1 → 8.50enisa_euvdEU
Citrix Systems Inc. Citrix ADC13.0 → 13.0-92.19fstec_bduRU
Citrix Systems Inc. Citrix ADC13.1 → 13.1-49.15fstec_bduRU
Citrix Systems Inc. Citrix ADC14 → 14.1-8.50fstec_bduRU
Citrix Systems Inc. Citrix Gateway13.0 → 13.0-92.19fstec_bduRU
Citrix Systems Inc. Citrix Gateway13.1 → 13.1-49.15fstec_bduRU
Citrix Systems Inc. Citrix Gateway14 → 14.1-8.50fstec_bduRU
citrix netscaler application delivery controller12.1 → 12.1-55.300nvdUScpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:*:*:*:*
citrix netscaler application delivery controller13.0 → 13.0-92.19nvdUScpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:*:*:*:*
citrix netscaler application delivery controller13.1 → 13.1-37.164nvdUScpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:*:*:*:*
citrix netscaler application delivery controller13.1 → 13.1-49.15nvdUScpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:*:*:*:*
citrix netscaler application delivery controller14.1 → 14.1-8.50nvdUScpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:*:*:*:*

showing 20 of 23

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2023-2605Citrix Systems ADC: Mehrere SchwachstellenDeutsch2023-10-10csaf · cert_bundDE
Ein entfernter anonymer Angreifer kann mehrere Schwachstellen in Citrix Systems ADC und Citrix Systems Citrix Gateway ausnutzen, um Informationen offenzulegen oder einen Denial-of-Service-Zustand auszulösen.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd cert_bund NVD CVE.org MITRE

published 2023-10-10modified 2026-07-31

references (9)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan