Netscaler Application Delivery ControllerApplication · Citrix

CVE-2025-7775

CRITICAL · 9.8 CVSS v3.1 Published 2025-08-26

Fix available

A fix is available. Upgrade to 12.1-55.330 / 13.1-37.241 or later.

See remediation →

100/100

Remediation priority · Urgent

In the wild Remotely reachable No privileges Zero-click

Official description

NVD · unedited

Memory overflow vulnerability leading to Remote Code Execution and/or Denial of Service in NetScaler ADC and NetScaler Gateway when NetScaler is configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server (OR) NetScaler ADC and NetScaler Gateway 13.1, 14.1, 13.1-FIPS and NDcPP: LB virtual servers of type (HTTP, SSL or HTTP_QUIC) bound with IPv6 services or servicegroups bound with IPv6 servers (OR) NetScaler ADC and NetScaler Gateway 13.1, 14.1, 13.1-FIPS and NDcPP: LB virtual servers of type (HTTP, SSL or HTTP_QUIC) bound with DBS IPv6 services or servicegroups bound with IPv6 DBS servers (OR) CR virtual server with type HDX

Technical summary

dbcve analysis · high confidence

Memory overflow (buffer overflow) vulnerability in NetScaler ADC and Gateway allows remote attackers to execute arbitrary code or cause denial of service. The flaw affects specific configurations: Gateway virtual servers (VPN, ICA Proxy, CVPN, RDP Proxy), AAA virtual servers, and certain load balancing configurations using IPv6 services with HTTP/SSL/HTTP_QUIC types, as well as CR virtual servers of type HDX.

MitigationApply vendor patches for affected versions (13.1, 14.1, 13.1-FIPS, NDcPP). If immediate patching is not possible, consider disabling or restricting access to affected virtual server configurations as a temporary mitigation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions

NVD · CPE data

Netscaler Application Delivery ControllerApplication

Affected:>= 12.1, < 12.1-55.330>= 13.1, < 13.1-37.241>= 13.1, < 13.1-59.22>= 14.1, < 14.1-47.48

Netscaler GatewayApplication

Affected:>= 13.1, < 13.1-59.22>= 14.1, < 14.1-47.48

CVSS breakdown

From the vector

Attack vector: Network
Complexity: Low
Privileges: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

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

Am I affected?

dbcve checks

Work through these to decide whether this CVE applies to you.

Identify NetScaler product type and version

Run 'show version' or 'nsversion' command on the NetScaler CLI to determine if the device is running NetScaler ADC or NetScaler Gateway and note the exact build number

Affected if Version is 12.1 < build < 12.1-55.330, OR 13.1 < build < 13.1-37.241, OR 13.1 < build < 13.1-59.22, OR 14.1 < build < 14.1-47.48 (check all ranges that apply to your release)
Check for Gateway virtual server configurations

Run 'show vserver' and look for virtual servers of type VPN, ICA_PROXY, CVPN, or RDP_PROXY

Affected if Any Gateway-type virtual servers (VPN virtual server, ICA Proxy, CVPN, or RDP Proxy) are configured and the version is in the affected range
Check for AAA virtual server

Run 'show aaa vserver' to list any AAA virtual servers configured on the device

Affected if Any AAA virtual server is configured and the version is in the affected range
Check LB virtual servers with IPv6 services

Run 'show lb vserver' and for each HTTP/SSL/HTTP_QUIC type vserver, run 'show service <service_name>' to check if bound services use IPv6 addresses

Affected if LB virtual servers of type HTTP, SSL, or HTTP_QUIC are bound to IPv6 services or servicegroups, and version is in affected range
Check for CR virtual server type HDX

Run 'show cr vserver' and identify any Content Routing virtual servers configured with HDX type

Affected if CR virtual server of type HDX is configured and version is in affected range

The environment is affected if the NetScaler ADC or Gateway version falls within the specified vulnerable build ranges AND one of the specific virtual server types (Gateway, AAA, LB with IPv6, or CR HDX) is configured.

Generated from the published advisory. Verify against your own configuration.

Remediation

dbcve · scoped

Upgrade available Upgrade to 12.1-55.330 / 13.1-37.241 / 13.1-59.22 or later

Fixed in 12.1-55.33013.1-37.24113.1-59.22

Interim mitigation

Apply vendor patches for affected versions (13.1, 14.1, 13.1-FIPS, NDcPP). If immediate patching is not possible, consider disabling or restricting access to affected virtual server configurations as a temporary mitigation.

Recommended fix High confidence

Upgrade to 12.1-55.330+ for 12.1 branch; 13.1-59.22+ for 13.1 branch; 14.1-47.48+ for 14.1 branch

1. Identify the currently installed NetScaler ADC or NetScaler Gateway version using 'show version' or 'nsversion' command
2. Determine which release branch you are on (12.1, 13.1, or 14.1)
3. For 12.1.x deployments: Plan upgrade to version 12.1-55.330 or later
4. For 13.1.x deployments: Plan upgrade to version 13.1-59.22 or later (this covers all mentioned attack vectors)
5. For 14.1.x deployments: Plan upgrade to version 14.1-47.48 or later
6. Before upgrading, backup the current configuration using 'create backup' command
7. Review Citrix NetScaler upgrade documentation for your specific version
8. Schedule maintenance window as upgrade may cause brief service interruption

Caveat Review release notes for potential behavioral changes; some legacy configurations may require adjustment after upgrade

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Netscaler Application Delivery Controller Exploited in the wild — priority engagement

Consultation4.0 h
Implementation8.0 h
Testing12.0 h
Review / QA4.0 h

28.0 hours of engineering $4,760

Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,616.

Scan for this in your stack

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References

Primary sources

support.citrix.comVendor Advisory
www.cisa.govUS Government Resource
nvd.nist.govNVD record

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-7775 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2025-7775?

The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.

The version that genuinely resolved it — not the one the vendor claimed
A config change or rule that shut the vector down
A gotcha in the upgrade path that cost you an afternoon

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here

Verified mitigations, workarounds, and config changes
Version or environment caveats, and links to real fixes
No weaponised exploit code, or anything meant to cause harm
No spam, self-promotion, credentials, or personal data

At a glance

Exploited in the wildOn CISA’s known-exploited list · agencies must fix by 2025-08-28

A fix existsUpgrade to 12.1-55.330 / 13.1-37.241 or later

Severity 9.8 Critical

Exploit likelihood EPSS, next 30 days 19.6%

Affects: Netscaler Application Delivery Controller

Remediation

Being exploited — close it fast

Fix this in Netscaler Application Delivery Controller 28 hrs · Moderate

Typical engagement from $4,760

Get it fixed fast See the full breakdown ↓

This CVE is on CISA’s actively-exploited list, so the clock is real — a vetted specialist can deliver a reviewed fix for your staging environment quickly.

You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

Check your environment

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

Scan for this in your stack

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Am I affected?

Remediation

References