CISA flags active exploits of BeyondTrust flaw
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CISA warns attackers are exploiting a critical authentication bypass (CVE-2026-102764) in BeyondTrust Remote Support to gain initial access and escalate privileges.
CISA has added CVE-2026-102764, a critical authentication bypass vulnerability in BeyondTrust Remote Support (formerly Bomgar), to its Known Exploited Vulnerabilities catalog. The flaw affects self-hosted Remote Support appliances running version 26.2.3 and earlier; BeyondTrust-hosted SaaS instances have already been patched. Threat actors are actively exploiting the vulnerability, tracked under the activity name ARMORY CASTLE by BeyondTrust and Mandiant, to gain initial access to appliances, establish persistence, escalate privileges, and move laterally within victim networks.
BeyondTrust has released patch BT26-05-RS for supported versions (24.3.1 and later); organizations running older self-hosted versions must first upgrade before applying the patch. CISA urges immediate patching, restricting external and administrative access to Remote Support appliances to trusted networks, and conducting network and memory forensics to detect compromise. Indicators of compromise include unrecognized privileged sessions, unexpected script files, gaps in logging, and unauthorized account or session-policy changes.
Organizations that suspect compromise should isolate affected appliances, preserve forensic images, forward logs to their SIEM, and—critically—rebuild from a known-good state after patching, rotate all credentials the appliance stored or injected, revoke active support sessions, and review new MFA registrations on privileged accounts. CISA references Mandiant's ARMORY CASTLE blog and BeyondTrust's BT26-05 advisory for detailed hunting and detection guidance.
Mentioned in this report
Source reporting: https://www.cisa.gov/news-events/alerts/2026/10/16/cisa-urges-patching-critical-vulnerability-beyondtrust-remote-support
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