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Weekly Signal
Live intelligence Updated 19 Aug 2026 · 12:58 UTC

Citrix · NetScaler ADC and Gateway, Netscaler Application Delivery Controller, Netscaler Gateway

CVE-2025-5777

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

Recommended action

Treat this as an immediate remediation priority. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

View response plan
CVSS9.3
EPSS100.0%
KEVYes
ExploitationConfirmed exploitation
PatchPatch or guidance available ↓

Assessment

Why it matters

CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 100.0%; technical severity is CVSS 9.3.

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

Who should care

  • Teams operating NetScaler ADC and Gateway, Netscaler Application Delivery Controller, Netscaler Gateway
  • Vulnerability and exposure management teams
  • Security operations teams monitoring exploitation activity

Response plan

What I would do

  1. Confirm whether NetScaler ADC and Gateway, Netscaler Application Delivery Controller, Netscaler Gateway is present in the environment.
  2. Identify affected versions and establish whether vulnerable services are exposed or reachable.
  3. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
  4. Review relevant security telemetry for evidence of attempted or successful exploitation.
  5. Document the remediation decision and track it to verified completion.

Vendor remediation

Patch and remediation links

Use the vendor source below to confirm the correct fixed version, package or mitigation for your affected product.

Technical details

CVSS vector
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
CWE
CWE-125
Affected versions
Citrix NetScaler ADC and Gateway; Citrix Netscaler Application Delivery Controller (Start Including: 14.1, End Excluding: 14.1-43.56); Citrix Netscaler Gateway (Start Including: 14.1, End Excluding: 14.1-43.56)
Published
17 June 2025
Attack vector
Network
Privileges required
None
User interaction
None

Signal timeline

  1. CVE published
  2. Added to CISA KEV
  3. Latest EPSS score: 100.0%
  4. Signal calculated at 87

External references

Live public intelligence This assessment combines public-source evidence. Validate the affected product, version and exposure against your own environment before making a risk decision.