Citrix NetScaler

2026-07-0610 minCheck Pointcritical

This weekly threat intelligence bulletin covers multiple active ransomware campaigns, four critical vulnerabilities under active exploitation, and emerging AI-driven threats. Notable items include actively exploited RCE flaws in Oracle E-Business Suite and Progress Kemp LoadMaster, a Citrix NetScaler memory disclosure flaw exploited within 24 hours of disclosure, a North Korean supply-chain campaign (PolinRider) deploying 108 malicious packages, and a proof-of-concept browser-native ransomware generated by an LLM abusing Chrome's File System Access API.

Token Theft and AI Poisoning Redefine the Perimeter Attackers are shifting from breaking passwords to stealing active login sessions, bypassing multi-factor authentication entirely. This week, ARToken and ConsentFix exploited Microsoft 365 OAuth flows to hijack accounts, while Anubis ransomware used the ongoing CitrixBleed 2 vulnerability to steal session tokens from network gateways. Even a standard user can become a Global Administrator in minutes if identity settings are loose, as demonstrated by a recent M365 privilege escalation analysis. Simultaneously, artificial intelligence systems have evolved from helper tools to critical vulnerabilities, serving as both the weapon and the target. Threat actors are using AI to generate malware like InfernoGrabber v9.0 and BusySnake Stealer, while also poisoning AI agent ecosystems with malicious skills like OpenClaw and tricking AI models into executing financial fraud via indirect prompt injection. The AI arms race has accelerated breakout times to under 30 minutes, with state-sponsored groups like GTG-1002 now orchestrating entire espionage campaigns via AI. Defenders must immediately audit identity and session controls, treating session tokens as highly sensitive credentials. Security teams should also implement guardrails for AI agents, verifying external URLs and restricting autonomous financial or code execution actions.

2026-07-0112 minArctic Wolfcritical

Arctic Wolf Labs documents Anubis ransomware affiliate tradecraft observed across multiple 2026 intrusions, featuring CitrixBleed 2 (CVE-2025-5777) exploitation and valid VPN credential abuse for initial access. Affiliates consistently deploy legitimate RMM tools for persistence, use Mimikatz and ntds.dit extraction for credential access, establish alternate egress via cloudflared and SSH SOCKS tunnels, and employ exfiltration tools like S3 Browser and rclone before deploying encryptors on Windows and Linux systems. The attack chain relies on commodity tools and living-off-the-land techniques that resemble legitimate administration in isolation but form a distinctive kill chain when correlated.

A new pre-auth memory overread vulnerability, CVE-2026-8451 (CVSS 8.8), has been disclosed in Citrix NetScaler ADC and Gateway appliances configured as SAML Identity Providers. The flaw resides in the custom XML parser handling SAML AuthnRequest messages, where unquoted attribute values terminated by newlines cause the parser to read beyond the buffer boundaries. This leaked memory, which may include sensitive data or pointers, is returned to the attacker via the NSC_TASS cookie, and the issue can also be triggered to crash the nsppe process.

2026-07-016 minCanadian Centre for Cyber Securitycritical

The Canadian Centre for Cyber Security published a daily advisory digest on 2026-06-30 covering four security advisories for SimpleHelp, wolfSSL, Mozilla Firefox, and Citrix NetScaler ADC/Gateway. The most urgent item is CVE-2026-48558 in SimpleHelp, which has been added to CISA's KEV Database, indicating active exploitation. Citrix NetScaler ADC and Gateway also have multiple critical vulnerabilities across versions 13.1 and 14.1 that require immediate attention.

2026-05-137 minSophoscritical

Threat actors are actively abusing the QEMU hardware emulator to create hidden virtual machines on compromised hosts, effectively shielding their attack toolkits from endpoint detection and response (EDR) solutions. Recent campaigns, including those linked to the PayoutsKing ransomware group, leverage this technique alongside vulnerability exploitation and legitimate remote access tools to establish persistence, harvest credentials, and exfiltrate data.

2026-05-135 minRecorded Futurecritical

In March 2026, 31 high-impact vulnerabilities were actively exploited, highlighted by the Interlock Ransomware Group leveraging a CVSS 10.0 zero-day in Cisco Secure FMC (CVE-2026-20131). The attackers utilized insecure Java deserialization to gain root access, deploying custom RATs, memory-resident web shells, and ransomware across enterprise networks.

2026-05-134 minCanadian Centre for Cyber Securitycritical

The Canadian Centre for Cyber Security released a daily digest of 10 security advisories highlighting critical vulnerabilities across multiple vendors. Notably, vulnerabilities in Fortinet FortiClientEMS (CVE-2026-21643) and Citrix NetScaler (CVE-2026-3055) are currently being exploited in the wild, requiring immediate patching and potential incident response actions if compromise is suspected.

2026-05-133 minCISAhigh

CISA has added CVE-2026-3055, an actively exploited out-of-bounds read vulnerability affecting Citrix NetScaler, to its Known Exploited Vulnerabilities (KEV) Catalog. The agency mandates federal remediation under BOD 22-01 and strongly urges all organizations to prioritize patching to reduce exposure to cyberattacks.

A second memory overread vulnerability has been identified in Citrix NetScaler appliances under CVE-2026-3055, affecting the '/wsfed/passive?wctx' endpoint. By sending a specially crafted GET request with an empty 'wctx' parameter, attackers can force the appliance to leak sensitive memory, including administrative session IDs, via the 'NSC_TASS' cookie. Active in-the-wild exploitation has been observed since late March.

2026-05-134 minNCSChigh

The NCSC has issued an alert regarding two vulnerabilities in customer-managed Citrix NetScaler ADC and Gateway appliances. CVE-2026-3055 allows for a memory overread in SAML IDP configurations, while CVE-2026-4368 causes user session mixups via a race condition in Gateway or AAA virtual server configurations. Immediate patching is strongly recommended.

2026-05-134 minCanadian Centre for Cyber Securitycritical

The Canadian Centre for Cyber Security released a daily digest of 9 security advisories covering critical vulnerabilities across major enterprise, Linux, and ICS platforms. Notably, a critical vulnerability in Craft CMS (CVE-2025-32432) is being actively exploited in the wild, and Citrix has patched critical flaws in NetScaler ADC and Gateway.

2026-05-138 minMandiantcritical

In 2025, ransomware operators increasingly relied on vulnerability exploitation for initial access and heavily targeted virtualization infrastructure like ESXi. While overall ransomware profitability appears to be declining, threat actors have adapted by increasing data theft extortion, targeting smaller organizations, and utilizing cross-platform ransomware families like REDBIKE, AGENDA, and INC.