CVSS base score: 9.3 (Critical) vendor CNA · v4.0
Score assigned by the vendor's own CVE Numbering Authority (CNA); CISA's Vulnrichment program adds a score only when the CNA omits one.
Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability
Vendor: Citrix Product: NetScaler
Citrix NetScaler ADC and NetScaler Gateway contain an authentication-bypass vulnerability involving an alternate path or channel. When the NetScaler appliance is configured as an AAA virtual server or as a Gateway (SSL VPN, ICA Proxy, CVPN, or RDP Proxy), an unauthenticated remote threat actor may be able to bypass authentication.
Each milestone comes from a different source, so gaps between them are gaps in what those sources publish, not evidence that nothing happened. EPSS history for this CVE holds 17 points from 2026-08-22, tracked daily from 2026-09-09; earlier points are weekly, which dates a spike to within a week. Peak probability 6.0% on 2026-09-10.
Check whether a specific version is affected →
What each source publishes about which product versions carry this vulnerability, kept as written rather than merged. Absence here means no source has published applicability data, not that nothing is affected.
| Date | Source | Article |
|---|---|---|
| 2026-09-04 | BleepingComputer | Critical Citrix NetScaler auth bypass now leveraged in attacks |
| 2026-08-24 | Check Point Research | 24th August – Threat Intelligence Report |
Articles from monitored vendor research blogs and security news feeds that specifically mention this CVE. Coverage begins when feed monitoring started; earlier articles are not indexed.
Coverage across public collections only: Nuclei and OpenVAS NVT (scan);
Snort and Suricata ET Open (network); Sigma and YARA (host/SIEM);
Metasploit, Exploit-DB and public GitHub repositories (exploit). Absence
here means nothing public was found, not that detection is impossible.
GitHub PoC repositories are collected automatically by
PoC-in-GitHub (CC0) and are not vetted:
some are fakes and some are malware. Treat them as evidence that code was
published, not as code to run.
OpenVAS coverage derives from the Greenbone Community Feed, made available
under the Open Database License (ODbL) v1.0;
its individual Vulnerability Tests are licensed
GNU GPL v2.
Defensive techniques inferred by MITRE D3FEND from the underlying weakness (CWE-288) — general hardening and detection guidance for this weakness class, not a vendor patch for this specific CVE.
| Source | Date | Record |
|---|---|---|
| CISA Vulnrichment | 2026-08-20 | source record → |
| CISA KEV | 2026-09-09 | source record → |
| Date | Advisory | Issuer |
|---|---|---|
| 2026-09-09 | CISA Adds Four Known Exploited Vulnerabilities to Catalog | CISA |
| 2026-09-04 | CRITICAL ALERT: Critical vulnerabilities in Citrix NetScaler Application Delivery Controller (ADC) and Citrix NetScaler Gateway products | ASD/ACSC |
| 2026-08-19 | 2026-010: Critical Vulnerabilities in Citrix NetScaler ADC and NetScaler Gateway | CERT-EU |
No exploit-tool sightings recorded for this CVE.
Evidence tiers are explained on the About page — a merged Metasploit module is far stronger evidence than a distro package mention.
CVE.org record → NVD entry → CISA KEV catalog → FortiGuard Labs → Rapid7 AttackerKB →