CVE-2025-5777

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

As of , CVE-2025-5777 in Citrix NetScaler ADC and Gateway is on CISA's list of exploited vulnerabilities: CISA listed it on . Our patch-first group: Patch this week.

Exploited
Yes: CISA listed it on 10 July 2025
US federal deadline
11 July 20251 day after CISA listed it. US federal civilian agencies must fix it by then.
Used in ransomware campaigns
KnownCISA changed it from Unknown to Known on 18 August 2025.
EPSS score
0.99Higher than 99% of the CVEs EPSS scores. EPSS estimates the chance of exploitation activity in the next 30 days.
Public exploit
1 Exploit-DB entry
Fix
Vendor advice: support.citrix.comLinks below, from CISA's entry.

What CISA says to do

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's required action

What the flaw is

Citrix NetScaler ADC and Gateway contain an out-of-bounds read vulnerability due to insufficient input validation. This vulnerability can lead to memory overread when the NetScaler is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server.

CISA's 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

The CVE record's description, from Citrix

CVE published
17 June 2025
Assigned by
Citrix
CVSS
9.3 Critical (CVSS 4.0, from the CNA)
CWE-125
Out-of-bounds Read
CWE-457
Use of Uninitialized Variable
CISA SSVC, exploitation
active
CISA SSVC, automatable
yes
CISA SSVC, technical impact
total

Timeline

  1. The CVE record was published.
  2. CISA added it to its list of exploited vulnerabilities.
  3. The US federal deadline to fix it.
  4. Exploit-DB published an exploit (EDB-ID 52401).
  5. CISA changed its entry. Ransomware use: Unknown to Known.

Public exploits

Facts from Metasploit's module list and Exploit-DB's index; we never copy exploit code.

NetScaler ADC and Gateway: other exploited entries

VulnerabilityProductOur groupListedDeadlineEPSS
CVE-2025-6543Buffer OverflowCitrix NetScaler ADC and GatewayPatch soon0.11

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