Critical NetScaler Vulnerability Exploited in Attacks
CISA added critical Citrix NetScaler flaw CVE-2026-19490 (CVSS 9.3) to its KEV catalog after confirming exploitation of gateway and AAA virtual servers in the wild.
CISA warned that threat actors are exploiting CVE-2026-19490, a critical-severity flaw (CVSS 9.3) affecting NetScaler ADC and NetScaler Gateway appliances configured as a gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server. Citrix patched the bug on August 19, and Rapid7 warned it is remotely exploitable without authentication. Sensor data from Previdian shows exploitation ongoing since at least September 3, one day after a public exploit appeared on GitHub, with matching requests observed from three IPs across three countries. CISA added the flaw to its Known Exploited Vulnerabilities catalog, giving federal agencies three days to patch under BOD 26-04.
- CISA added CVE-2026-19490 to the KEV catalog, requiring federal agencies to patch within three days.
- Flaw affects NetScaler ADC and Gateway appliances configured as SSL VPN, ICA Proxy, CVPN, RDP Proxy, or AAA virtual servers.
- Citrix patched the 9.3-severity bug on August 19; Rapid7 said it is remotely exploitable without authentication.
- Sensor telemetry shows exploitation since at least September 3, following a public exploit on GitHub.
- CVEs
- CVE-2026-19490
- Products
- NetScaler ADCNetScaler Gateway
Vulnerabilities mentioned
All| CVE | Vulnerability | CVSS | EPSS | Signals | Published |
|---|---|---|---|---|---|
| CVE-2026-19490 | Remote Authentication Bypass in Citrix NetScaler ADC and NetScaler Gateway | 9.3 | 33% | KEVPoC | KEV |
From the original article
1 min read at securityweek.com
Tracked as CVE-2026-19490, the authentication bypass flaw has been exploited in the wild since at least September 3. The post Critical NetScaler Vulnerability Exploited in Attacks appeared first on SecurityWeek.
By Ionut Arghire · securityweek.com
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