CVE-2025-7775: Citrix NetScaler

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

Yes, if you run Citrix NetScaler. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-08-26, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-08-28; treat that as the outer limit, not the target.
EPSS 20.3%, percentile 97: FIRST’s model estimates a 20.3% chance of exploitation activity in the next 30 days, higher than 97% of all scored CVEs (very high). EPSS is a probability, not a verdict.
Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

What it is

Memory overflow vulnerability leading to Remote Code Execution and/or Denial of Service in NetScaler ADC and NetScaler Gateway when NetScaler is configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server (OR) NetScaler ADC and NetScaler Gateway 13.1, 14.1, 13.1-FIPS and NDcPP: LB virtual servers of type (HTTP, SSL or HTTPQUIC) bound with IPv6 services or servicegroups bound with IPv6 servers (OR) NetScaler ADC and NetScaler Gateway 13.1, 14.1, 13.1-FIPS and NDcPP: LB virtual servers of type (HTTP, SSL or HTTPQUIC) bound with DBS IPv6 services or servicegroups bound with IPv6 DBS servers (OR) CR virtual server with type HDX

CISA’s summary

Citrix NetScaler ADC and NetScaler Gateway contain a memory overflow vulnerability that could allow for remote code execution and/or denial of service.

Weakness type: CWE-119.

Product: Citrix NetScaler · Assigned by: Citrix · Published: 2025-08-26

Affected and fixed versions

Vendor	Product	Affected versions (per CVE record)
NetScaler	ADC	14.1 < 47.48, 13.1 < 59.22, 13.1 FIPS and NDcPP < 37.241, 12.1 FIPS and NDcPP < 55.330
NetScaler	Gateway	14.1 < 47.48, 13.1 < 59.22, 13.1 FIPS and NDcPP < 37.241, 12.1 FIPS and NDcPP < 55.330

Severity scores

Scored by	CVSS	Score	Vector
Citrix	4.0	9.2 Critical	`CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L`

Attack vector: network (remotely reachable)
Attack complexity: high (needs special conditions)
Attack requirements: present (depends on deployment conditions)
Privileges required: none (no login)
User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

CISA KEV: added 2025-08-26; federal due date 2025-08-28. Known ransomware use: Unknown.
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.
CISA SSVC assessment: exploitation active, automatable no, technical impact total.
FIRST EPSS (model of 2026-10-21): 20.28% probability of exploitation activity in the next 30 days; percentile 97.

Timeline

2025-08-26 — Added to CISA’s Known Exploited Vulnerabilities catalog
2025-08-26 — CVE record published by Citrix
2025-08-28 — CISA remediation deadline for US federal agencies
2026-02-26 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.