CVE-2025-5777

Name: CVE-2025-5777
Creator: NVD / NIST
Published: 2025-06-17T13:15:21.523+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.3/10Actively ExploitedEPSS 99.90%

Last modified Jun 17, 2026

CVE-2025-5777 is a critical-severity vulnerability rated 9.3/10 on the CVSS scale. 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. CISA has confirmed active exploitation in the wild. EPSS estimates a 99.90% chance of exploitation in the next 30 days.

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

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS 4.0

9.3/10

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

99.90%

100.0th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Jul 11, 2025.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Citrix	Netscaler Application Delivery Controller	>= 12.1, < 12.1-55.328
Citrix	Netscaler Application Delivery Controller	>= 13.1, < 13.1-37.235
Citrix	Netscaler Application Delivery Controller	>= 13.1, < 13.1-58.32
Citrix	Netscaler Application Delivery Controller	>= 14.1, < 14.1-43.56
Citrix	Netscaler Gateway	>= 13.1, < 13.1-58.32
Citrix	Netscaler Gateway	>= 14.1, < 14.1-43.56

References

https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX693420Vendor Advisory
https://citrixbleed.comBroken Link, Third Party Advisory
https://horizon3.ai/attack-research/attack-blogs/cve-2025-5777-citrixbleed-2-write-up-maybe/Third Party Advisory
https://labs.watchtowr.com/how-much-more-must-we-bleed-citrix-netscaler-memory-disclosure-citrixbleed-2-cve-2025-5777/Third Party Advisory
https://www.bleepingcomputer.com/news/security/cisa-tags-citrix-bleed-2-as-exploited-gives-agencies-a-day-to-patch/Press/Media Coverage, Third Party Advisory
https://www.netscaler.com/blog/news/netscaler-critical-security-updates-for-cve-2025-6543-and-cve-2025-5777/Third Party Advisory
https://www.theregister.com/2025/07/10/cisa_citrixbleed_kev/Press/Media Coverage
https://doublepulsar.com/citrixbleed-2-exploitation-started-mid-june-how-to-spot-it-f3106392aa71Third Party Advisory
https://reliaquest.com/blog/threat-spotlight-citrix-bleed-2-vulnerability-in-netscaler-adc-gateway-devices/Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-5777US Government Resource

Timeline

Published: Jun 17, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

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 score of 9.3/10 (CRITICAL severity). The EPSS model estimates a 99.90% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2025-5777?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-5777?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST