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 ...

Here’s an overview of some of last week’s most interesting news, articles, interviews and videos: 16-year-old researcher breaks into Microsoft analytics service with access to 17 trillion rows of data A flaw in Titan, an internal Microsoft analytics service, could have let an attacker read employee records and Bing search analytics, a 16-year-old security researcher has disclosed. Citrix NetScaler RCE zero-days exploited globally for weeks (CVE-2026-88771, CVE-2026-88772) Citrix has patched eight critical and high-severity vulnerabilities … More → The post Week in review: Researcher breaks into Microsoft analytics service, NetScaler RCE 0-day exploited appeared first on Help Net Security .

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.

Mandiant and GTIG detail active exploitation of a Citrix NetScaler zero-day, deploying custom web shells WHIPSHOT and SLAPSHOT for root access. Mandiant and Google Threat Intelligence Group caught active exploitation of a zero-day in Citrix NetScaler ADC and Gateway appliances in late September 2026. The bug, tracked as CVE-2026-88772 (CVSS score of 9.5), has been […]

Cybersecurity researchers have disclosed technical details of a recently patched critical security flaw in Citrix NetScaler ADC and Gateway that has come under active exploitation in the wild. The vulnerability, tracked as CVE-2026-88772 (CVSS score: 9.5), has been described as a memory overflow bug in the Datagram Transport Layer Security (DTLS) protocol handling that's rooted in the NetScaler

Cybersecurity firms say attackers exploited the Citrix NetScaler CVE-2026-88772 zero-day to deploy custom web shells and tunneling malware, gain root access, steal credentials, and spread into internal networks. [...]

The hacking of internet-exposed, vulnerable Citrix NetScaler ADC and Gateway deployments has escalated. What started as stealthy targeting via zero-day exploits has now become widespread “spray and pray” exploitation, fueled by the publication of a root-cause analysis and a proof-of-concept exploit for CVE-2026-88771, which is remotely exploitable on unpatched devices with the default configuration. From rumor to confirmed zero-day Rumors about a NetScaler zero-day being exploited in the wild started late last week, and were … More → The post NetScaler zero-day exploitation escalates into mass attacks (CVE-2026-88771) appeared first on Help Net Security .

Unit 42 is aware of possible 0-day activity against NetScaler devices. Citrix reports CVE-2026-88771, CVE-2026-88772 have been exploited in the wild. The post Threat Brief: NetScaler Zero Days CVE-2026-88771 and CVE-2026-88772 Exploited in the Wild appeared first on Unit 42 .

Citrix has patched eight critical and high-severity vulnerabilities in NetScaler ADC and NetScaler Gateway, two of which (CVE-2026-88771, CVE-2026-88772) have been exploited in zero-day attacks to plant webshells on compromised devices. Rumors about their existence and active exploitation popped up on Reddit on Friday, fueled by warnings from IT suppliers, who apparently got the information from the Dutch National Cyber Security Center (NCSC-NL). According to security researcher Kevin Beaumont, European government sources have been warning … More → The post Citrix NetScaler RCE zero-days exploited globally for weeks (CVE-2026-88771, CVE-2026-88772) appeared first on Help Net Security .