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Citrix has released updates to address two security flaws impacting NetScaler ADC and NetScaler Gateway deployments, including a critical-severity authentication bypass vulnerability. According to the cloud computing and virtualization technology company, the issues affect customer-managed NetScaler ADC and NetScaler Gateway, including certain FIPS and NDcPP builds, as well as SecurAccess ZTNA Hybrid deployments that use customer-managed NetScaler instances. It bears noting that the vulnerabilities do not apply to Citrix-managed cloud services or Citrix-managed Adaptive Authentication, as the necessary updates have already been applied. The list of impacted NetScaler versions is below - NetScaler ADC and NetScaler Gateway 14.1 BEFORE 14.1-73.32  NetScaler ADC and NetScaler Gateway 13.1 BEFORE 13.1-63.21  NetScaler ADC FIPS BEFORE 14.1-73.32 FIPS  NetScaler ADC FIPS and NDcPP BEFORE 13.1-37.277  The first of the two vulnerabilities is CVE-2026...

Citrix has released patches for yet another critical security flaw impacting NetScaler ADC and NetScaler Gateway that could result in remote code execution or denial-of-service (DoS) under certain conditions. " CVE-2026-107406 is a memory overflow vulnerability that may lead to remote code execution or denial-of-service under specific configuration conditions," Citrix said. The vulnerability carries a CVSS score of 9.5 out of 10.0. There is no evidence that the issue has been exploited in the wild. Citrix has credited Michael Tucker, Chew Keong Tan, and Alex Bernier of the JPMorgan Chase XOR Team, along with Maxim Suhanov, for discovering and reporting the flaw. Successful exploitation hinges on the NetScaler deployments being configured as a SAML identity provider (IdP) or service provider (SP). Customers can determine if their instances meet the criteria by checking the configuration for entries like below - SAML SP: add authentication samlAction SAML IdP: ...

Two critical vulnerabilities in Citrix NetScaler ADC and NetScaler Gateway that allow remote code execution have been exploited in the wild, Citrix confirmed on September 27. It released fixes for both, along with six other flaws. One of the two affects every deployment on an affected version, including those in the default configuration. The bulletin came a day after security firm watchTowr said two unpatched NetScaler RCE flaws had been exploited, and after some administrators said they had taken appliances offline. Citrix did not say whether its two flaws are the ones watchTowr described, but they match that account. NetScaler ADC and NetScaler Gateway sit at the edge of enterprise networks, where they handle VPN and remote access, load balancing, and user authentication. Citrix said in its bulletin that the two exploited flaws are: CVE-2026-88771 (CVSS v4 score: 9.5) - An improper input validation flaw that lets an unauthenticated attacker run arbitrary commands. It a...

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Sunday added two critical Citrix NetScaler ADC and Gateway flaws to its Known Exploited Vulnerabilities ( KEV ) catalog, following reports of active exploitation. The vulnerabilities are listed below - CVE-2026-88771 (CVSS score: 9.5) - An improper input validation vulnerability that could allow an unauthenticated attacker to execute arbitrary commands.  CVE-2026-88772 (CVSS score: 9.5) - An improper restriction of operations within the bounds of a memory buffer vulnerability that could allow for remote code execution or denial-of-service. While CVE-2026-88771 affects all NetScaler ADC and NetScaler Gateway deployments, CVE-2026-88772 requires the DTLS configuration to be enabled on NetScaler ADC or NetScaler Gateway, an option that is turned on by default on VPN virtual servers. The relevant configuration is as follows - add vpn vserver vpn1 SSL 10.0.0.0 443 -Listenpolicy NONE 

Citrix has released fixes to address three security flaws in NetScaler ADC and NetScaler Gateway, including one that it said has been actively exploited in the wild. The vulnerabilities in question are listed below - CVE-2025-7775 (CVSS score: 9.2) - Memory overflow vulnerability leading to Remote Code Execution and/or Denial-of-Service CVE-2025-7776 (CVSS score: 8.8) - Memory overflow vulnerability leading to unpredictable or erroneous behavior and Denial-of-Service CVE-2025-8424 (CVSS score: 8.7) - Improper access control on the NetScaler Management Interface The company acknowledged that "exploits of CVE-2025-7775 on unmitigated appliances have been observed," but stopped short of sharing additional details. However, for the flaws to be exploited, there are a number of prerequisites - CVE-2025-7775 - NetScaler must be configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server; NetScaler ADC and NetScaler Gateway 13.1, 14.1...

Citrix is  alerting  users of a critical security flaw in NetScaler Application Delivery Controller (ADC) and Gateway that it said is being actively exploited in the wild. Tracked as  CVE-2023-3519  (CVSS score: 9.8), the issue relates to a case of  code injection  that could result in unauthenticated remote code execution. It impacts the following versions - NetScaler ADC and NetScaler Gateway 13.1 before 13.1-49.13 NetScaler ADC and NetScaler Gateway 13.0 before 13.0-91.13 NetScaler ADC and NetScaler Gateway version 12.1 (currently end-of-life) NetScaler ADC 13.1-FIPS before 13.1-37.159 NetScaler ADC 12.1-FIPS before 12.1-55.297, and NetScaler ADC 12.1-NDcPP before 12.1-55.297 The company did not give further details on the flaw tied to CVE-2023-3519 other than to say that exploits for the flaw have been observed on "unmitigated appliances." However, successful exploitation requires the device to be configured as a Gateway (VPN virtual server, ...

Citrix has released security updates for a high-severity security flaw impacting NetScaler Console (formerly NetScaler ADM) and NetScaler Agent that could lead to privilege escalation under certain conditions. The vulnerability, tracked as CVE-2024-12284 , has been given a CVSS v4 score of 8.8 out of a maximum of 10.0. It has been described as a case of improper privilege management that could result in authenticated privilege escalation if the NetScaler Console Agent is deployed and allows an attacker to execute post-compromise actions. "The issue arises due to inadequate privilege management and could be exploited by an authenticated malicious actor to execute commands without additional authorization," Netscaler noted . "However, only authenticated users with existing access to the NetScaler Console can exploit this vulnerability, thereby limiting the threat surface to only authenticated users." The shortcoming affects the below versions - NetScaler Cons...

Citrix has released security updates for a high-severity security flaw in NetScaler ADC and NetScaler Gateway that has been exploited as part of targeted zero-day attacks. The vulnerability, tracked as CVE-2026-88779 , carries a CVSS score of 8.7 out of 10.0. "CVE-2026-88779 is a memory overflow vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway that can lead to denial-of-service under specific deployment conditions," Citrix said . "The issue affects customer-managed NetScaler deployments running affected supported versions when the required preconditions are met." For successful exploitation, NetScaler ADC or NetScaler Gateway must be configured either as a SAML service provider (SP) or SAML identity provider(IdP). Customers can check if their NetScaler deployment meets the precondition by reviewing their configuration for entries matching the following - SAML SP - add authentication samlAction SAML IdP - add authentication samlIdPPro...

Citrix has released security updates to address a critical flaw affecting NetScaler ADC that it said has been exploited in the wild. The vulnerability, tracked as CVE-2025-6543 , carries a CVSS score of 9.2 out of a maximum of 10.0. It has been described as a case of memory overflow that could result in unintended control flow and denial-of-service. However, successful exploitation requires the appliance to be configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server. The shortcoming impacts the below versions - NetScaler ADC and NetScaler Gateway 14.1 prior to 14.1-47.46  NetScaler ADC and NetScaler Gateway 13.1 prior to 13.1-59.19 NetScaler ADC and NetScaler Gateway 12.1 and 13.0 (vulnerable and end-of-life) NetScaler ADC 13.1-FIPS and NDcPP prior to 13.1-37.236-FIPS and NDcPP "Secure Private Access on-prem or Secure Private Access Hybrid deployments using NetScaler instances are also affected by the vulnerabilities," Citrix ...

Citrix is warning of two zero-day security vulnerabilities in NetScaler ADC (formerly Citrix ADC) and NetScaler Gateway (formerly Citrix Gateway) that are being actively exploited in the wild. The flaws are listed below - CVE-2023-6548 (CVSS score: 5.5) - Authenticated (low privileged) remote code execution on Management Interface (requires access to NSIP, CLIP, or SNIP with management interface access) CVE-2023-6549 (CVSS score: 8.2) - Denial-of-service (requires that the appliance be configured as a Gateway or authorization and accounting, or AAA, virtual server) The following customer-managed versions of NetScaler ADC and NetScaler Gateway are impacted by the shortcomings - NetScaler ADC and NetScaler Gateway 14.1 before 14.1-12.35 NetScaler ADC and NetScaler Gateway 13.1 before 13.1-51.15 NetScaler ADC and NetScaler Gateway 13.0 before 13.0-92.21 NetScaler ADC and NetScaler Gateway version 12.1 (currently end-of-life) NetScaler ADC 13.1-FIPS before 13.1-37.176 NetS...

Citrix on Tuesday released security updates to address multiple flaws in NetScaler ADC (formerly Citrix ADC) and NetScaler Gateway (formerly Citrix Gateway) that could be exploited by an attacker to facilitate arbitrary file reads or trigger a denial-of-service (DoS) condition. The vulnerabilities are listed below - CVE-2026-8451 (CVSS score: 8.8) - An insufficient input validation vulnerability leading to memory overread when NetScaler ADC or NetScaler Gateway is configured as a SAML IDP CVE-2026-8452 (CVSS score: 8.8) - A memory overflow vulnerability leading to unpredictable or erroneous behavior and denial-of-service when the appliance is configured as a Gateway or an AAA virtual server CVE-2026-8655 (CVSS score: 8.8) - Multiple memory overflow vulnerabilities leading to unpredictable or erroneous behavior and denial-of-service when NetScaler ADC is configured as an LB of type Oracle, a DNS Proxy, or a DNS recursive resolver deployment CVE-2026-10816 (CVSS sco...

A recently disclosed critical security flaw impacting Citrix NetScaler ADC and NetScaler Gateway is witnessing active reconnaissance activity, according to Defused Cyber and watchTowr . The vulnerability, CVE-2026-3055 (CVSS score: 9.3), refers to a case of insufficient input validation leading to memory overread, which an attacker could exploit to leak potentially sensitive information. Per Citrix, successful exploitation of the flaw hinges on the appliance being configured as a SAML Identity Provider (SAML IDP). "We are now observing auth method fingerprinting activity against NetScaler ADC/Gateway in the wild," Defused Cyber said in a post on X. "Attackers are probing /cgi/GetAuthMethods to enumerate enabled authentication flows in our Citrix honeypots." This is likely an attempt on the part of threat actors to determine if NetScaler ADC and NetScaler Gateway are indeed configured as a SAML IDP. In a similar warning, watchTowr said it has detected active...

Citrix is warning of exploitation of a recently disclosed critical security flaw in NetScaler ADC and Gateway appliances that could result in exposure of sensitive information. Tracked as  CVE-2023-4966  (CVSS score: 9.4), the vulnerability impacts the following supported versions - NetScaler ADC and NetScaler Gateway 14.1 before 14.1-8.50 NetScaler ADC and NetScaler Gateway 13.1 before 13.1-49.15 NetScaler ADC and NetScaler Gateway 13.0 before 13.0-92.19 NetScaler ADC and NetScaler Gateway 12.1 (currently end-of-life) NetScaler ADC 13.1-FIPS before 13.1-37.164 NetScaler ADC 12.1-FIPS before 12.1-55.300, and NetScaler ADC 12.1-NDcPP before 12.1-55.300 However, for exploitation to occur, it requires the device to be configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or authorization and accounting (AAA) virtual server. While patches for the flaw were released on October 10, 2023, Citrix has now revised the advisory to note that "exploits of CV...

Cybersecurity researchers have detailed two now-patched security flaws in SAP Graphical User Interface (GUI) for Windows and Java that, if successfully exploited, could have enabled attackers to access sensitive information under certain conditions. The vulnerabilities, tracked as CVE-2025-0055 and CVE-2025-0056 (CVSS scores: 6.0), were patched by SAP as part of its monthly updates for January 2025 . "The research discovered that SAP GUI input history is stored insecurely, both in the Java and Windows versions," Pathlock researcher Jonathan Stross said in a report shared with The Hacker News. SAP GUI user history allows users to access previously entered values in input fields with the goal of saving time and reducing errors. This historical information is stored locally on devices. This can include usernames, national IDs, social security numbers (SSNs), bank account numbers, and internal SAP table names. The vulnerabilities identified by Pathlock are rooted in th...

Threat actors have been observed exploiting a critical pre-authentication command injection vulnerability in Citrix NetScaler ADC and NetScaler Gateway to drop web shells and attempt theft of configuration data. LevelBlue's Threat Hunt Operations & Research (THOR) team, which analyzed the exploitation activity across multiple customer environments, said it identified malicious NetScaler authentication events containing attacker-controlled usernames designed to weaponize CVE-2026-88771. CVE-2026-88771 (CVSS score: 9.5) is an improper input validation vulnerability that could allow an unauthenticated attacker to execute arbitrary commands.  The security flaw, along with CVE-2026-88772, was disclosed last week after reports that the Dutch National Cyber Security Centre (NCSC-NL) reportedly sent a pre-notification to organizations in the Netherlands that urged organizations to shut their appliances down, citing active exploitation. As of writing, there are currently no d...

Nearly 2,000 Citrix NetScaler instances have been compromised with a backdoor by weaponizing a recently disclosed critical security vulnerability as part of a large-scale attack. "An adversary appears to have exploited CVE-2023-3519 in an automated fashion, placing web shells on vulnerable NetScalers to gain persistent access," NCC Group  said  in an advisory released Tuesday. "The adversary can execute arbitrary commands with this webshell, even when a NetScaler is patched and/or rebooted." CVE-2023-3519 refers to a critical code injection vulnerability impacting NetScaler ADC and Gateway servers that could lead to unauthenticated remote code execution. It was patched by Citrix last month. The development comes a week after the Shadowserver Foundation  said  it identified close to 7,000 vulnerable, unpatched NetScaler ADC and Gateway instances online and the flaw is being abused to drop PHP web shells on vulnerable servers for remote access. A follow-up anal...

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) issued an advisory on Thursday warning that the newly disclosed critical security flaw in Citrix NetScaler Application Delivery Controller (ADC) and Gateway devices is being abused to drop web shells on vulnerable systems. "In June 2023, threat actors exploited this vulnerability as a zero-day to drop a web shell on a critical infrastructure organization's non-production environment NetScaler ADC appliance," the agency  said . "The web shell enabled the actors to perform discovery on the victim's active directory (AD) and collect and exfiltrate AD data. The actors attempted to move laterally to a domain controller but network segmentation controls for the appliance blocked movement." The shortcoming in question is  CVE-2023-3519  (CVSS score: 9.8), a code injection bug that could result in unauthenticated remote code execution. Citrix, earlier this week, released patches for the issue and ...

Citrix has released security updates to address two vulnerabilities in NetScaler ADC and NetScaler Gateway, including a critical flaw that could be exploited to leak sensitive data from the application. The vulnerabilities are listed below - CVE-2026-3055 (CVSS score: 9.3) - Insufficient input validation leading to memory overread CVE-2026-4368 (CVSS score: 7.7) - Race condition leading to user session mixup Cybersecurity company Rapid7 said that CVE-2026-3055 refers to an out-of-bounds read that could be exploited by unauthenticated remote attackers to leak potentially sensitive information from the appliance's memory. However, for exploitation to be successful, the Citrix ADC or Citrix Gateway appliance must be configured as a SAML Identity Provider (SAML IDP), which means default configurations are unaffected. To determine if the device has been configured as a SAML IDP Profile, Citrix is urging customers to inspect their NetScaler Configuration for the specified st...

The Dutch National Cyber Security Centre (NCSC-NL) has warned of cyber attacks exploiting a recently disclosed critical security flaw impacting Citrix NetScaler ADC products to breach organizations in the country. The NCSC-NL said it discovered the exploitation of CVE-2025-6543 targeting several critical organizations within the Netherlands, and that investigations are ongoing to determine the extent of the impact. CVE-2025-6543 (CVSS score: 9.2) is a critical security vulnerability in NetScaler ADC that results in unintended control flow and denial-of-service (DoS) when the devices are configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server. The vulnerability was first disclosed in late June 2025, with patches released in the following versions - NetScaler ADC and NetScaler Gateway 14.1 prior to 14.1-47.46 NetScaler ADC and NetScaler Gateway 13.1 prior to 13.1-59.19 NetScaler ADC 13.1-FIPS and NDcPP prior to 13.1-37.236-FIPS and NDcPP ...

Unknown threat actors have been observed exploiting a newly patched security flaw in Citrix NetScaler ADC and NetScaler Gateway appliances to target organizations in North America and Europe. The activity, observed by Mandiant Consulting and Google Threat Intelligence Group (GTIG) in September 2026, has targeted government, financial services, technology, education, and legal and professional services sectors. In a post shared on LinkedIn, Charles Carmakal, chief technology officer at Mandiant Consulting, said the targeted intrusions have impacted dozens of organizations, warning of "broad and opportunistic exploitation of CVE-2026-88772 and CVE-2026-88771 by a variety of threat actors in the near term." "Exploitation of CVE-2026-88772 bypasses authentication and triggers an unhandled termination of the NetScaler Packet Processing Engine (NSPPE) to establish initial root-level access," the tech giant said . The attacks have been observed weaponizing the f...