CVE-2025-5777 Citrix NetScaler ADC and Gateway Out-of-Bounds Read
Attackers can read sensitive memory contents when NetScaler is configured as a Gateway or AAA virtual server due to insufficient input validation.
- Exploited in the wild
- Since 10 Jul 2025
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-5777?
CVE-2025-5777 is a critical vulnerability in NetScaler ADC, published on 17 Jun 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Insufficient input validation leading to memory overread when the NetScaler is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server
Which versions are affected by CVE-2025-5777?
It affects 2 products.
Products include Citrix NetScaler ADC, Citrix Netscaler Gateway.
How do I fix CVE-2025-5777?
No fix has been published for CVE-2025-5777 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 11 Jul 2025.
Is CVE-2025-5777 being exploited?
Yes. Attackers have exploited CVE-2025-5777 in the wild since at least 10 Jul 2025, including in ransomware campaigns.
Public exploit code: 1 Exploit-DB entry, 1 Nuclei template and 26 proofs of concept on GitHub.
Other vulnerabilities in NetScaler ADC
- CVE-2023-3519 Citrix NetScaler ADC and NetScaler Gateway Code Injection
- CVE-2026-88771 Citrix NetScaler Improper Input Validation
- CVE-2026-88772 Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer
- CVE-2023-4966 Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow
- CVE-2026-19490 Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel
Sources
Also known as GHSA-29vj-j5w5-pcph.