CVE-2026-19490 — Netscaler Application Delivery Controller
CRITICALCVE-2026-19490 is a critical-severity (CVSS 9.8) CWE-288 vulnerability in citrix netscaler application delivery controller. It is in CISA's Known Exploited Vulnerabilities catalog (added 2026-09-09) — treat it as actively exploited and patch now. A fix is available — see the affected versions and patch details below.
Vulnerability in NetScaler ADC and NetScaler Gateway. This issue affects ADC: from 14.1 through 73.32 and from 13.1 through 63.21; Gateway: from 14.1 through 73.32 and from 13.1 through 63.21.
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2026-09-09. Federal agencies were required to remediate by 2026-09-12.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2026-19490.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-19490 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 382,574 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Counts from FIRST.org, log-scaled.
Description
Vulnerability in NetScaler ADC and NetScaler Gateway.
This issue affects ADC: from 14.1 through 73.32 and from 13.1 through 63.21; Gateway: from 14.1 through 73.32 and from 13.1 through 63.21.
Affected Products
netscaler application delivery controllercitrixnetscaler gatewaycitrixResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every citrix netscaler application delivery controller deployment and check each version against the affected-products list above.
Fix
Apply the citrix netscaler application delivery controller security patch or hotfix for CVE-2026-19490 on the affected version, following the vendor advisory for your exact build.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
Frequently Asked Questions
Is CVE-2026-19490 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.