Intelligence online17 sources monitored8 actively exploited 7d26 published 24hChecked recently
Vulnerability record

CVE-2025-5777

Citrix NetScaler ADC and Gateway Out-of-Bounds Read Vulnerability

CriticalExploitation confirmedCISA KEV Used by ransomware
What should I do?

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run NetScaler ADC and Gateway, fix it now.

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.

US federal civilian agencies must remediate by Jul 11, 2025.

Patch status

No official fix confirmed yet

Until a fix ships, follow the vendor's mitigations and CISA's required action, limit exposure of affected systems, and watch this record for a patch.

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

Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.

Affected products

ProductVendorSource
NetScaler ADC and GatewayCitrix (Cloud Software Group)KEV

Sources: KEV = CISA Known Exploited Vulnerabilities catalog. Version details have not been published yet.

Intelligence timeline

Developments from the last 30 days, newest first.

  1. CVSS scoredUpdateKEV

    CVE-2025-5777 scored CVSS 9.3: Citrix NetScaler ADC and Gateway, Citrix NetScaler ADC and Gateway Out-of-Bounds Read Vulnerability

    CISA lists this as exploited in the wild and known to be used in ransomware campaigns. Unpatched NetScaler ADC and Gateway systems are exposed to active attacks now.

    Basis: NIST National Vulnerability Database

1 earlier event is available with a subscription. See plans.

Coverage

We have not published a story about this vulnerability yet.

References

  • support.citrix.com https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX693420
  • nvd.nist.gov https://nvd.nist.gov/vuln/detail/CVE-2025-5777
  • citrixbleed.com https://citrixbleed.com
  • horizon3.ai https://horizon3.ai/attack-research/attack-blogs/cve-2025-5777-citrixbleed-2-write-up-maybe/
  • labs.watchtowr.com https://labs.watchtowr.com/how-much-more-must-we-bleed-citrix-netscaler-memory-disclosure-citrixbleed-2-cve-20…
  • bleepingcomputer.com https://www.bleepingcomputer.com/news/security/cisa-tags-citrix-bleed-2-as-exploited-gives-agencies-a-day-to-p…
  • netscaler.com https://www.netscaler.com/blog/news/netscaler-critical-security-updates-for-cve-2025-6543-and-cve-2025-5777/
  • theregister.com https://www.theregister.com/2025/07/10/cisa_citrixbleed_kev/
  • doublepulsar.com https://doublepulsar.com/citrixbleed-2-exploitation-started-mid-june-how-to-spot-it-f3106392aa71
  • reliaquest.com https://reliaquest.com/blog/threat-spotlight-citrix-bleed-2-vulnerability-in-netscaler-adc-gateway-devices/
  • cisa.gov https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-5777