Last updated: August 19, 2026 at 1:47 AM UTC
All 741 Vulnerability 286 Breach 129 Threat 319 Defense 7
Tag: citrixbleed (2 articles)Clear

Anubis ransomware hides in legitimate remote-management tools after breaching via Citrix

Arctic Wolf detailed how affiliates of the Anubis ransomware group break in and stay hidden, drawing on intrusions across healthcare, finance, and manufacturing this year. Initial access came from stolen VPN credentials and from exploiting CitrixBleed 2, a NetScaler flaw that leaks session tokens from memory and lets attackers bypass multi-factor authentication. Once inside, the affiliates leaned on legitimate remote-management software such as ScreenConnect, Zoho Assist, and MeshAgent to blend in with normal IT activity, moving through networks with RDP and PsExec toward domain controllers, backups, and storage devices. They stole data using common cloud-transfer tools before encrypting anything, which is exactly where defenders have the best chance to catch them.

Check
Patch NetScaler against CitrixBleed 2 and terminate all active sessions afterward, then audit your environment for remote-management tools like ScreenConnect, Zoho Assist, or MeshAgent that IT did not deploy.
Affected
Organizations running unpatched Citrix NetScaler Gateways or reusable VPN credentials; Anubis affiliates use these to get in, then hide inside legitimate remote-management tools while stealing data ahead of encryption.
Fix
Patch CitrixBleed 2 and kill existing sessions, enforce phishing-resistant MFA on VPNs, allowlist approved remote-management tools and alert on any others, and watch for RMM installs and exfiltration tools clustering together.

Citrix patches six NetScaler flaws, including a CitrixBleed-style memory leak

Citrix has released fixes for six vulnerabilities in NetScaler ADC and NetScaler Gateway, including a high-severity memory-disclosure flaw that researchers place in the same class as the 2023 CitrixBleed bug. That flaw (CVE-2026-8451, rated 8.8) leaks small amounts of memory through malformed SAML requests and shares a root cause with an earlier NetScaler bug that was exploited within days of disclosure. The bulletin also covers an unauthenticated arbitrary file read and several denial-of-service issues, with CVSS scores from 6.9 to 8.8. No exploitation has been reported yet, but NetScaler appliances have drawn more than 20 entries on CISA's exploited-vulnerabilities list in three years, several used in ransomware.

Check
Inventory NetScaler ADC and Gateway appliances and their configurations, checking whether they run as SAML identity providers, expose management IPs, or use HTTP/2, and confirm which builds they are on.
Affected
NetScaler ADC and Gateway appliances on affected builds (CVE-2026-8451 and five others); SAML identity-provider setups risk memory disclosure, and other configurations face arbitrary file read or denial of service.
Fix
Update to NetScaler ADC and Gateway 14.1-72.61 or later fixed builds, and for the HTTP/2 denial-of-service flaw, manually set the Http2SmallWndTimeout parameter, since patching alone does not fully close it.