Citrix NetScaler ADC and Gateway Out-of-Bounds Read Vulnerability
NetScaler — ADC
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
9.3
99.9%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (Vulnerable System)
- High
- Integrity (Vulnerable System)
- High
- Availability (Vulnerable System)
- High
- Confidentiality (Subsequent System)
- Low
- Integrity (Subsequent System)
- Low
- Availability (Subsequent System)
- Low
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L
- Published
- Jun 17, 2025
- Modified
- Feb 26, 2026
- Added to KEV
- Jul 10, 2025
- Federal patch due
- Jul 11, 2025
CISA required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Weakness classification
Proof-of-concept & exploitation references
Weaponization
Public repositories whose name or description references CVE-2025-5777, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit - cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
No public GitHub repositories referencing CVE-2025-5777 were found at last check. Absence here is not proof no exploit exists - see the references below for vendor advisories and write-ups.
References
Frequently asked questions
What is CVE-2025-5777?
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
How severe is CVE-2025-5777?
CVE-2025-5777 has a CVSS base score of 9.3 out of 10 (CVSS 4.0).
Is CVE-2025-5777 actively exploited in the wild?
Yes. CVE-2025-5777 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Jul 10, 2025, meaning CISA has confirmed evidence of active exploitation. It is also flagged as used in ransomware campaigns.
What is the EPSS score for CVE-2025-5777?
99.9% - meaning FIRST.org's EPSS model estimates a 99.9% probability this vulnerability will be exploited in the wild within 30 days (100% percentile among all scored CVEs).
Is there exploit tooling available for CVE-2025-5777?
Yes - a public Nuclei template referencing CVE-2025-5777 exist in public repositories we checked.
What type of vulnerability is CVE-2025-5777?
CVE-2025-5777 is classified under CWE-125, CWE-457 (CWE-125 Out-of-bounds Read).
Cross-checked against
Impactr finds and proves whether CVE-2025-5777 - or flaws like it - are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.
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