CVE-2026-88773Network attack vector

Request smuggling via inconsistent HTTP parsing

Published Sep 27, 2026 · Updated Sep 27, 2026

HTTP request smuggling in Citrix NetScaler ADC and NetScaler Gateway allows remote attackers to desynchronize HTTP traffic. The products inconsistently interpret requests handled by HTTP or SSL LB, CS, VPN, or Authentication virtual servers; Citrix has not disclosed the specific parsing discrepancy. Exposure requires one of those virtual-server types, and crafted requests can cause a front end and back end to disagree on request boundaries.

CVSS severityUnavailable
Unscored
EPSS probability0.36%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTP request smuggling in Citrix NetScaler ADC and NetScaler Gateway allows remote attackers to desynchronize HTTP traffic. The products inconsistently interpret requests handled by HTTP or SSL LB, CS, VPN, or Authentication virtual servers; Citrix has not disclosed the specific parsing discrepancy. Exposure requires one of those virtual-server types, and crafted requests can cause a front end and back end to disagree on request boundaries.

The record

CVE
CVE-2026-88773
Published
Sep 27, 2026
Updated
Sep 27, 2026
Vendor
Citrix
Product
Citrix ADC
Classifications
CWE-444, T1190
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <13.1-37.279 and NDcPP
  2. Affected versionversion=0 <13.1-64.23
  3. Affected versionversion=0 <14.1-73.37
  4. Affected versionversion=0 <14.1-73.37 FIPS

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

Citrix · Citrix ADCversion=0 <13.1-37.279 and NDcPP; version=0 <13.1-64.23; version=0 <14.1-73.37; version=0 <14.1-73.37 FIPS
Citrix · Citrix Gatewayversion=0 <13.1-64.23; version=0 <14.1-73.37 FIPS

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-444Inconsistent Interpretation of HTTP Requests
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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