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Critical security vulnerability in Citrix Gateway and Netscaler ADC

Heise.De • March 23, 2026

The manufacturer "Cloud Software Group" has fixed two security vulnerabilities in the Citrix products "Netscaler ADC" (Application Delivery Controller) and "Gateway", one of them with a critical rating. The errors were noticed during an internal review, and updates have already been released. Citrix customers should quickly check if they are affected and update their appliances.

The two security vulnerabilities in detail:

The discerning reader of the Citrix security advisory must for details with a magnifying glass, but some details are reminiscent of the fatal security vulnerability CitrixBleed 2 from 2025. This also consisted of a memory leak that remote attackers could exploit to intercept access tokens. In conjunction with the now additionally reported race condition, they could use this specifically to take over certain user accounts.

Admins should quickly update to the updated versions:

This article was originally published in German . It was translated with technical assistance and editorially reviewed before publication.

The full story

This article is one source in a clustered incident — the cluster page carries the summary, timeline and every other outlet covering it.

Critical Vulnerabilities in Citrix NetScaler ADC and Gateway Require Immediate Patching Cloud Software Group has identified and patched two critical vulnerabilities in Citrix NetScaler ADC and Gateway products. The vulnerabilities, tracked as CVE-2026-3055, allow unauthenticated remote attackers to exploit memory overreads and potentially leak sensitive data. Organizations using these systems are urged to apply the updates immediately to mitigate risks. The vulnerabilities were discovered during an internal review and have been addressed in a security bulletin issued on March 23, 2026. The CVSS score for CVE-2026-3055 is 9.3, indicating a high level of severity. Affected organizations should refer to Citrix Security Bulletin CTX696300 for detailed information and remediation steps. The urgency of the situation is underscored by the potential for exploitation leading to serious data breaches. Administrators are advised to prioritize these updates to protect their systems from possible attacks. 30 sources 73

Extracted Entities

Critical security vulnerability in Citrix Gateway and Netscaler ADC

The full story

Extracted Entities

Attack Types (1)

MITRE ATT&CK (1)

Platforms (2)

Vulnerabilities (1)