NetScaler ADC and NetScaler Gateway - Insufficient input validation leading to memory overread

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2025-5777
StatePUBLISHED
AssignerCitrix
Source PriorityCVE Program / NVD first with legacy fallback
Published2025-06-17 13:15:21 UTC
Updated2026-08-04 05:16:35 UTC
DescriptionInsufficient 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

Risk And Classification

Primary CVSS: v4.0 9.3 CRITICAL from [email protected]

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: 0.999590000 probability, percentile 0.999760000 (date 2026-08-13)

CISA KEV: Listed on 2025-07-10; due 2025-07-11; ransomware use Known

Problem Types: CWE-125 | CWE-908 | CWE-457 | CWE-125 CWE-125 Out-of-bounds Read | CWE-457 CWE-457 Use of Uninitialized Variable

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary9.3CRITICALCVSS: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/C...
4.0CNACVSS9.3CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L
3.1[email protected]Primary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Sub Conf.
Low
Sub Integrity
Low
Sub Availability
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/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

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

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

CISA Known Exploited Vulnerability

VendorCitrix
ProductNetScaler ADC and Gateway
NameCitrix NetScaler ADC and Gateway Out-of-Bounds Read Vulnerability
Required ActionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Noteshttps://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX693420 ; https://nvd.nist.gov/vuln/detail/CVE-2025-5777

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Citrix Netscaler Application Delivery Controller All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA NetScaler ADC affected 14.1 43.56 patch Not specified
CNA NetScaler ADC affected 13.1 58.32 patch Not specified
CNA NetScaler Gateway affected 14.1 43.56 patch Not specified
CNA NetScaler Gateway affected 13.1 58.32 patch Not specified

References

ReferenceSourceLinkTags
citrixbleed.com af854a3a-2127-422b-91ae-364da2661108 citrixbleed.com Broken Link, Third Party Advisory
horizon3.ai/attack-research/attack-blogs/cve-2025-5777-citrixbleed-2-writ... af854a3a-2127-422b-91ae-364da2661108 horizon3.ai Third Party Advisory
www.netscaler.com/blog/news/netscaler-critical-security-updates-for-cve-2025-65... af854a3a-2127-422b-91ae-364da2661108 www.netscaler.com Third Party Advisory
www.theregister.com/2025/07/10/cisa_citrixbleed_kev af854a3a-2127-422b-91ae-364da2661108 www.theregister.com Press/Media Coverage
www.bleepingcomputer.com/news/security/cisa-tags-citrix-bleed-2-as-exploited-gives-age... af854a3a-2127-422b-91ae-364da2661108 www.bleepingcomputer.com Press/Media Coverage, Third Party Advisory
support.citrix.com/support-home/kbsearch/article [email protected] support.citrix.com Vendor Advisory
reliaquest.com/blog/threat-spotlight-citrix-bleed-2-vulnerability-in-netscal... 134c704f-9b21-4f2e-91b3-4a467353bcc0 reliaquest.com Third Party Advisory
doublepulsar.com/citrixbleed-2-exploitation-started-mid-june-how-to-spot-it-f3... 134c704f-9b21-4f2e-91b3-4a467353bcc0 doublepulsar.com Third Party Advisory
www.cisa.gov/known-exploited-vulnerabilities-catalog 134c704f-9b21-4f2e-91b3-4a467353bcc0 www.cisa.gov US Government Resource
labs.watchtowr.com/how-much-more-must-we-bleed-citrix-netscaler-memory-disclosur... af854a3a-2127-422b-91ae-364da2661108 labs.watchtowr.com Third Party Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
CISA Known Exploited Vulnerabilities catalog CISA www.cisa.gov kev

Additional Advisory Data

SourceTimeEvent
ADP2025-07-10T00:00:00.000ZCVE-2025-5777 added to CISA KEV

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