CitrixBleed 2 (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
Also Known as CitrixBleed 2
CitrixBleed 2 is the name researchers gave to a memory overread flaw in NetScaler ADC and Gateway, published by Citrix on June 17, 2025. watchTowr and Horizon3.ai both published analyses under this name in July 2025.
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:LExploitation Context
as of October 14, 2026- CISA added CVE-2025-5777 to the KEV catalog 23 days after its CVE record was published. The median for entries added in 2025 is 26 days.
- It is one of 27 Citrix entries in the CISA KEV catalog, and one of 5 added in 2025.
- Its current EPSS score (100.0%) is higher than that of 95% of CISA KEV entries.
Affected Products
| Vendor | Product | Affected versions |
|---|---|---|
| NetScaler | NetScaler ADC | 14.1 to <43.56 13.1 to <58.32 |
| NetScaler | 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 Citrix
Memory overflow vulnerability leading to unintended control flow and Denial of Service
Citrix ADC, Gateway, and SD-WAN WANOP Appliance Code Execution Vulnerability
Unauthenticated sensitive information disclosure
Citrix NetScaler ADC and NetScaler Gateway Code Injection Vulnerability
Related
Tool categories
CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.