Citrix fixes 8 vulnerabilities

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[TLP:CLEAR] Citrix fixes 8 vulnerabilities

Citrix NetScaler fixes 8 vulnerabilities in its products, two of which have been marked as actively exploited [1]. A selection of the most severe ones can be found below. Products and their fixed versions: NetScaler ADC [1]: 13.1-37.279 FIPS, 13.1-37.279 NDcPP, 13.1-64.23; 14.1-73.37; 14.1-73.37 FIPS NetScaler Gateway [1]: 13.1-64.23, 14.1-73.37

Citrix NetScaler ADC & Gateway - RCE (CVE-2026-88771)

CVSS 9.5 (Critical)

An unauthenticated remote attacker can execute arbitrary commands in the default configuration. The vendor warns of active exploitation of the vulnerability [1].

The vulnerability is present in products:

Citrix NetScaler ADC; >=13.1 FIPS, <13.1.37.279 FIPS; >=13.1 NDcPP, <13.1.37.279 NDcPP; >=13.1, <13.1-64.23; >=14.1, <14.1-73.37; >=14.1 FIPS, <14.1-73.37 FIPS;
Citrix NetScaler Gateway; >=13.1, <13.1-64.23; >=14.1, <14.1-73.37;

CVSS: 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

More information:

CVE-2026-88771 at cve.org, NVD
CWE-20: Improper Input Validation at cwe.mitre.org

The vulnerability was publicly disclosed 27. 9. 2026.

Citrix NetScaler ADC & Gateway - RCE, DoS (CVE-2026-88772)

CVSS 9.5 (Critical)

An unauthenticated remote attacker can execute arbitrary code or cause a DoS when the DTLS configuration is enabled (enabled by default on VPN vServers). The vendor warns of active exploitation of the vulnerability [1].

The vulnerability is present in products:

Citrix NetScaler ADC; >=13.1 FIPS, <13.1.37.279 FIPS; >=13.1 NDcPP, <13.1.37.279 NDcPP; >=13.1, <13.1-64.23; >=14.1, <14.1-73.37; >=14.1 FIPS, <14.1-73.37 FIPS;
Citrix NetScaler Gateway; >=13.1, <13.1-64.23; >=14.1, <14.1-73.37;

CVSS: 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

More information:

CVE-2026-88772 at cve.org, NVD
CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer at cwe.mitre.org

The vulnerability was publicly disclosed 27. 9. 2026.

Citrix NetScaler ADC & Gateway - HTTP request smuggling (CVE-2026-88773)

CVSS 9.3 (Critical)

An unauthenticated remote attacker can carry out HTTP request smuggling on HTTP or SSL type virtual servers [1].

The vulnerability is present in products:

Citrix NetScaler ADC; >=13.1 FIPS, <13.1.37.279 FIPS; >=13.1 NDcPP, <13.1.37.279 NDcPP; >=13.1, <13.1-64.23; >=14.1, <14.1-73.37; >=14.1 FIPS, <14.1-73.37 FIPS;
Citrix NetScaler Gateway; >=13.1, <13.1-64.23; >=14.1, <14.1-73.37;

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

More information:

CVE-2026-88773 at cve.org, NVD
CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') at cwe.mitre.org

The vulnerability was publicly disclosed 27. 9. 2026.

Citrix NetScaler ADC & Gateway - DoS (CVE-2026-88775)

CVSS 8.8 (High)

An unauthenticated remote attacker can cause unpredictable system behavior or a DoS in Gateway configurations (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or an AAA virtual server [1].

The vulnerability is present in products:

Citrix NetScaler ADC; >=13.1 FIPS, <13.1.37.279 FIPS; >=13.1 NDcPP, <13.1.37.279 NDcPP; >=13.1, <13.1-64.23; >=14.1, <14.1-73.37; >=14.1 FIPS, <14.1-73.37 FIPS;
Citrix NetScaler Gateway; >=13.1, <13.1-64.23; >=14.1, <14.1-73.37;

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

More information:

CVE-2026-88775 at cve.org, NVD
CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer at cwe.mitre.org

The vulnerability was publicly disclosed 27. 9. 2026.

Citrix NetScaler ADC & Gateway - session hijacking, DoS (CVE-2026-88778)

CVSS 8.8 (High)

An unauthenticated remote attacker can predict TCP sequence numbers on TCP virtual servers with the Enhanced ISN Generation feature disabled. As an immediate mitigation, the vendor recommends enabling this feature in the TCP configuration [1].

The vulnerability is present in products:

Citrix NetScaler ADC; >=13.1 FIPS, <13.1.37.279 FIPS; >=13.1 NDcPP, <13.1.37.279 NDcPP; >=13.1, <13.1-64.23; >=14.1, <14.1-73.37; >=14.1 FIPS, <14.1-73.37 FIPS;
Citrix NetScaler Gateway; >=13.1, <13.1-64.23; >=14.1, <14.1-73.37;

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

More information:

CVE-2026-88778 at cve.org, NVD
CWE-342: Predictable Exact Value from Previous Values at cwe.mitre.org

The vulnerability was publicly disclosed 27. 9. 2026.

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[TLP:CLEAR] Citrix fixes 8 vulnerabilities

Citrix NetScaler ADC & Gateway - RCE (CVE-2026-88771)

CVSS 9.5 (Critical)

Citrix NetScaler ADC & Gateway - RCE, DoS (CVE-2026-88772)

CVSS 9.5 (Critical)

Citrix NetScaler ADC & Gateway - HTTP request smuggling (CVE-2026-88773)

CVSS 9.3 (Critical)

Citrix NetScaler ADC & Gateway - DoS (CVE-2026-88775)

CVSS 8.8 (High)

Citrix NetScaler ADC & Gateway - session hijacking, DoS (CVE-2026-88778)

CVSS 8.8 (High)

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