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8.8
HIGH CVSS 4.0
CVE-2026-88778
TCP Initial Sequence Number (ISN) prediction
Overview
Description

Predictable exact value from previous values 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.

Details
INFO

Published Date :

Sept. 27, 2026, 5:16 p.m.

Last Modified :

Sept. 29, 2026, 5:17 p.m.

Remotely Exploit :

Yes !

Source :

50a63c94-1ea7-4568-8c11-eb79e7c5a2b5
Impact
Affected Products

The following products are affected by CVE-2026-88778 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Citrix netscaler_application_delivery_controller
2 Citrix netscaler_gateway
: Total Affected Vendor : 1 | Products : 2
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH [email protected]
CVSS 4.0 HIGH 50a63c94-1ea7-4568-8c11-eb79e7c5a2b5
CVSS 4.0 HIGH 50a63c94-1ea7-4568-8c11-eb79e7c5a2b5
Solution
Update Citrix NetScaler ADC and Gateway to the latest available versions to patch the vulnerability.
  • Update ADC versions before 14.1-73.37.
  • Update ADC versions before 13.1-64.23.
  • Update Gateway versions before 14.1-73.37.
  • Update Gateway versions before 13.1-64.23.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-88778.

URL Resource
https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096 Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-88778 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-88778 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-88778 vulnerability anywhere in the article.

  • Dark Reading
Kiteworks & Citrix Incidents Show Challenges of Zero-Day Response

5 Min ReadOn Sept. 24, threat detection firm GreyNoise Intelligence observed a single US-based IP address scanning for Citrix NetScaler installations and conducting remote code execution (RCE) attacks ... Read more

Published Date: Oct 02, 2026 (2 weeks, 1 day ago)
  • The Hacker News
CISA Says Attackers Are Exploiting Two Critical Citrix NetScaler Flaws Globally

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 rep ... Read more

Published Date: Sep 28, 2026 (2 weeks, 5 days ago)
  • TheCyberThrone
Citrix NetScaler Zero-Days Exploited in the Wild: CISA Adds Them to KEV

Executive SummaryCitrix has confirmed that two NetScaler ADC and NetScaler Gateway zero-day vulnerabilities — CVE-2026-88771 and CVE-2026-88772 — are being exploited in the wild.Both are rated CVSS 9. ... Read more

Published Date: Sep 28, 2026 (2 weeks, 6 days ago)

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-88778 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Sep. 29, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-88778', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-09-29T16:34:20.349812Z'}
  • Initial Analysis by [email protected]

    Sep. 28, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
    Added CPE Configuration OR *cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:* versions from (including) 13.1 up to (excluding) 13.1-64.23 *cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:* versions from (including) 14.1 up to (excluding) 14.1-73.37 *cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:* versions from (including) 13.1 up to (excluding) 13.1.37.279 *cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:* versions from (including) 14.1-66.68 up to (including) 14.1-73.37 *cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:ndcpp:*:*:* versions from (including) 13.1 up to (excluding) 13.1.37.279 *cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:* versions from (including) 13.1 up to (excluding) 13.1-64.23 *cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:* versions from (including) 14.1 up to (excluding) 14.1-73.37
    Added Reference Type NetScaler: https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096 Types: Vendor Advisory
  • CVE Translated by [email protected]

    Sep. 28, 2026

    Action Type Old Value New Value
    Added Translation Title: ADC y Gateway de Citrix NetScaler, Description: Vulnerabilidad de valor exacto predecible a partir de valores anteriores en Citrix NetScaler ADC y Citrix NetScaler Gateway. Este problema afecta a ADC: versiones anteriores a 14.1-73.37, anteriores a 13.1-64.23, anteriores a 14.1-73.37 FIPS, y anteriores a 13.1.37.279 FIPS y NDcPP; Gateway: versiones anteriores a 14.1-73.37 y anteriores a 13.1-64.23.
  • New CVE Received by 50a63c94-1ea7-4568-8c11-eb79e7c5a2b5

    Sep. 27, 2026

    Action Type Old Value New Value
    Added Description Predictable exact value from previous values 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:H/SC:L/SI:L/SA:L/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
    Added CWE CWE-342
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/88xxx/CVE-2026-88778.json">CVE-2026-88778</a>
    Added Reference https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 8.8
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
VS Integrity
VS Availability
SS Confidentiality
SS Integrity
SS Availability
Base CVSS Score: 7.5
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact