CVE-2025-5777
NetScaler ADC and NetScaler Gateway - Insufficient input validation leading to memory overread
Citrix NetScaler ADC and Gateway Out-of-Bounds Read Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.
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.
CISA notes
https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX693420 ; https://nvd.nist.gov/vuln/detail/CVE-2025-5777
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
Severity
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:LAffected Products
| Vendor | Product | Affected versions |
|---|---|---|
| NetScaler | ADC | 14.1 to <43.56 13.1 to <58.32 |
| NetScaler | Gateway | 14.1 to <43.56 13.1 to <58.32 |
References
7 Links- https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX693420
- https://www.bleepingcomputer.com/news/security/cisa-tags-citrix-bleed-2-as-exploited-gives-agencies-a-day-to-patch/
- https://labs.watchtowr.com/how-much-more-must-we-bleed-citrix-netscaler-memory-disclosure-citrixbleed-2-cve-2025-5777/
- https://www.theregister.com/2025/07/10/cisa_citrixbleed_kev/
- https://horizon3.ai/attack-research/attack-blogs/cve-2025-5777-citrixbleed-2-write-up-maybe/
- https://www.netscaler.com/blog/news/netscaler-critical-security-updates-for-cve-2025-6543-and-cve-2025-5777/
- https://citrixbleed.com
Record Details
More from NetScaler
Memory overflow vulnerability leading to Remote Code Execution and/or Denial of Service
Memory overflow vulnerability leading to unintended control flow and Denial of Service
NetScaler ADC and NetScaler Gateway Security Bulletin for CVE-2026-19490
Insufficient input validation leading to memory overread
Related Tool Categories
Tool categories that test for or protect against this vulnerability class.
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