CISA has added another Citrix NetScaler vulnerability to its Known Exploited Vulnerabilities catalog on Sunday: CVE-2026-88779, a memory overflow bug that may cripple vulnerable NetScaler ADCs and Gateways. “Citrix has observed targeted attacks on unmitigated NetScaler deployments which can lead to Denial of Service. If the condition is triggered repeatedly, the service may remain unavailable,” the vendor stated. “Our analysis indicates that this issue affects service availability, and we have not identified an impact on … More → The post CISA flags new exploited NetScaler flaw as attackers crash appliances (CVE-2026-88779) appeared first on Help Net Security .

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

Citrix has released emergency updates for a new NetScaler denial-of-service vulnerability tracked as CVE-2026-88779 that has been exploited in zero-day attacks, with researchers investigating whether it can also be exploited for remote code execution. [...]

CISA has added one new vulnerability to its  Known Exploited Vulnerabilities (KEV) Catalog , based on evidence of active exploitation. CVE-2026-88779 Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability This type of vulnerability is a frequent attack vector for malicious cyber actors and poses significant risks to the federal enterprise. Binding Operational Directive (BOD) 26-04: Prioritizing Security Updates Based on Risk establishes vulnerability management requirements for Federal Civilian Executive Branch (FCEB) agencies. BOD 26-04 reinforces the importance of the KEV Catalog and requires federal agencies to prioritize rapid remediation of high-risk vulnerabilities, specifically those identified by Common Vulnerabilities and Exposures (CVEs) listed in CISA’s KEV Catalog on publicly exposed assets that grant total control of the asset post-exploitation, while deferring action for lower-risk vulnerabilities. BOD 26-04 further establishes basic expectations for when agencies must check whether threat actors compromised the system before the patch was applied. While BOD 26-04 applies only to FCEB agencies, CISA encourages all organizations to adopt risk-based vulnerability management and prioritize remediation of  KEV Catalog vulnerabilities . CISA will continue to add vulnerabilities to the catalog that meet the  specified criteria . Aware of an exploited vulnerability not currently listed in ...

Citrix NetScaler ADC (formerly Citrix ADC) and Citrix NetScaler Gateway (formerly Citrix Gateway) contain an improper restriction of operations within the bounds of a memory buffer vulnerability that could allow for a denial of service.