This weekly roundup highlights a range of cybersecurity developments affecting artificial intelligence platforms, enterprise software, healthcare organizations, social media accounts, and internet-facing infrastructure. 

From stolen Claude sessions and bypassed PaperCut security fixes to an attempted attack targeting hundreds of thousands of X users, recent incidents demonstrate how attackers continue to exploit both software vulnerabilities and active user sessions. 

The latest developments also show that organizations face growing risks across AI services, on-premises systems, enterprise edge devices, and account recovery infrastructure. Security teams are being urged to respond quickly as attackers increasingly target exposed systems and authentication mechanisms. 

The Cyber Express Weekly Roundup 

Anthropic Warns of Claude Session Hijacking 

Anthropic has warned that common infostealer malware is being used to steal active Claude sessions, potentially allowing attackers to bypass passwords and two-factor authentication. The campaign involves malware such as Vidar, LummaC2, RedLine, and Atomic Stealer, which is often distributed through pirated software and illicit downloads. Attackers may also consume victims’ paid AI usage. Read more… 

PaperCut Releases Second Emergency Patch After First Fix Is Bypassed 

PaperCut has released a second emergency patch for two actively exploited vulnerabilities affecting its NG and MF print management servers. Researchers discovered ways to bypass the initial security fix, potentially allowing attackers to chain the flaws and achieve pre-authentication remote code execution on exposed systems. Read more… 

Boston Scientific Cyberattack Limited to Certain On-Premises Systems 

Boston Scientific says its ongoing cybersecurity incident is limited to certain on-premises systems, with no impact identified on its cloud-based applications. The company has also reported no confirmed data breach or evidence of unauthorized activity since August 25, as its investigation into the incident continues. Read more… 

DOJ Investigates Attempted Cyberattack on Hundreds of Thousands of X Users 

The U.S. Department of Justice is investigating a large-scale cyberattack targeting hundreds of thousands of X accounts through the platform’s password-recovery system. Attorney General Todd Blanche said X detected and disrupted the campaign before the targeted accounts could be captured, preventing the attempted account takeover operation from succeeding. Read more… 

Two Citrix NetScaler Flaws Put Enterprise Edge Devices at Risk 

Two vulnerabilities in Citrix NetScaler ADC and Gateway have prompted an urgent patching warning from Australia’s cybersecurity agency. CVE-2026-19489, a memory overflow flaw, and CVE-2026-19490, an authentication bypass, can affect systems with specific configurations involving SIP ALG, SAML, or VPN gateway functionality. Read more… 

Weekly Cybersecurity Takeaway 

This week’s developments demonstrate that cybersecurity threats are increasingly targeting authentication systems, active user sessions, exposed enterprise infrastructure, and critical business applications. AI platforms, print management servers, healthcare environments, social media accounts, and network edge devices all remain potential targets for attackers. 

Organizations should prioritize rapid security patching, protection of active sessions, strong authentication controls, careful monitoring of exposed infrastructure, and timely investigation of suspicious activity. Security teams should also review systems that rely on password-recovery mechanisms and identify enterprise devices operating with vulnerable configurations. 

As businesses continue to rely on cloud services, AI platforms, remote access technologies, and internet-facing enterprise systems, attackers are finding new opportunities to exploit trusted sessions and security weaknesses. Organizations must maintain continuous monitoring and rapid response capabilities to reduce the impact of increasingly targeted cyberattacks.