Background exploitation KEV catalog No authentication

CVE-2025-7775

Citrix NetScaler Memory Overflow Vulnerability

CheckOps priority index

6.7/10 Patch within 7 days

Severity9.2

Probability2.1

Exploitation4/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 20.7% higher than 97.5% of CVEs

CVSS 4.0 9.2 AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/

Exploited for 434 days 26 Aug 2025

CISA due date 28 Aug 2025 for US federal agencies

Exploitation probability EPSS · FIRST

EPSS probability (%)Percentile among all CVEs

Exploitation signals 4 / 5

KEV catalog (CISA)26 Aug 2025
Exploited in EUVD (ENISA)26 Aug 2025
Used by ransomwareno
EPSS above 10 %20.7%
No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

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 HTTP_QUIC) 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 HTTP_QUIC) bound with DBS IPv6 services or servicegroups bound with IPv6 DBS servers (OR) CR virtual server with type HDX

Affected products

GatewayADCNetScaler

Affected versions

14.1 <47.48
13.1 FIPS and NDcPP <37.241
13.1 <59.22
12.1 FIPS and NDcPP <55.330

Weaknesses (CWE)

CWE-119

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

26 Aug 2025
Published
26 Aug 2025
Exploitation reported (ENISA)
26 Aug 2025
Added to the KEV catalog
28 Aug 2025
CISA remediation due date
26 Oct 2026
EPSS peak: 20.7%

References

Other exploited vulnerabilities from the same vendor

CVE-2026-88779Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability
6.2 · Actively exploited
CVE-2026-88772Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability
8.5 · Actively exploited
CVE-2026-88771Citrix NetScaler Improper Input Validation Vulnerability
8.7 · Actively exploited
CVE-2026-19490Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability
7.1 · Actively exploited
CVE-2026-8452Citrix NetScaler ADC and NetScaler Gateway Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability
5.4 · Actively exploited
CVE-2026-3055Citrix NetScaler Out-of-Bounds Read Vulnerability
8.9 · Background exploitation