# CVE-2025-5777: Citrix NetScaler ADC and Gateway out-of-bounds read

Source: https://junglewise.ai/threats/cve-2025-5777-citrix-netscaler-adc-and-gateway-out-of-bounds-read  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-07-10. Updated: 2026-05-15  
License: CC BY 4.0 with a link back

CVE-2025-5777 · Severity: critical · CVSS 9.3 · Exploited in the wild · Published 2025-07-10

Citrix NetScaler ADC and Gateway appliances, which are used to manage network traffic and provide secure remote access, contain a critical security flaw. This vulnerability allows an attacker to read sensitive information from the device's memory without needing a password. This could lead to the theft of session tokens or other private data, potentially allowing unauthorized access to corporate networks. This issue is actively being exploited in the wild.

Technologies: [Citrix Gateway](https://junglewise.ai/threats/technologies/gateway), [Citrix NetScaler ADC](https://junglewise.ai/threats/technologies/netscaler-adc). Vendors: [Citrix](https://junglewise.ai/threats/vendors/citrix).

## Quick answers

**Is CVE-2025-5777 exploited in the wild?** Yes. CVE-2025-5777 is known to be exploited in the wild, first recorded on 10 July 2025. Treat it as urgent.

**How severe is CVE-2025-5777?** Critical severity, with a CVSS score of 9.3, published 10 July 2025.

**Which products and versions are affected?** Citrix NetScaler ADC; Citrix NetScaler Gateway.

**Is there a fix for CVE-2025-5777?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2025-5777 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2025-5777?** Check whether you run Citrix Gateway, Citrix NetScaler ADC or Citrix NetScaler Gateway. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An out-of-bounds read vulnerability exists in Citrix NetScaler ADC and Gateway due to insufficient input validation. The flaw is triggered when the device is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or an AAA virtual server. A remote, unauthenticated attacker can exploit this by sending specially crafted requests to the appliance, leading to a memory overread. This can result in the disclosure of sensitive information, such as session cookies or memory-resident secrets, similar to the 'Citrix Bleed' vulnerability. Citrix has released security updates to address this issue, and CISA has confirmed active exploitation.

## Affected products

- Citrix NetScaler ADC
- Citrix NetScaler Gateway

## Timeline

- 2025-07-10: disclosed
- 2025-07-10: advisory
- 2025-07-10: kev added: Added to CISA KEV catalog due to active exploitation.
- 2025-07-10: exploited

## Related threats

- [Citrix NetScaler ADC memory overflow in LDAP authentication](https://junglewise.ai/threats/cve-2026-111342-memory-overflow-in-ldap-authentication-can-lead-to-unpredictable)
- [Citrix NetScaler memory overflow in client-certificate authentication](https://junglewise.ai/threats/cve-2026-111341-memory-overflow-in-client-certificate-authentication-can-lead-to)
- [Citrix NetScaler memory overflow in KBA authentication](https://junglewise.ai/threats/cve-2026-111340-memory-overflow-in-kba-knowledge-based-authentication-can-lead)
- [Citrix NetScaler ADC memory overflow in Email OTP authentication](https://junglewise.ai/threats/cve-2026-107415-memory-overflow-in-email-otp-authentication-can-lead-to)
- [Citrix NetScaler ADC memory overflow in WebAuth authentication](https://junglewise.ai/threats/cve-2026-107414-memory-overflow-in-webauth-authentication-can-lead-to)