Daily Security Briefing #252

May 12, 2026 | Read Online

GRIDTIDE disrupted, Claude Code vulnerabilities exposed, and AI training data poisoning…

Executive Summary

Cybersecurity threats continue to evolve with malicious actors adapting to disruptions. The recent GRIDTIDE campaign disruption highlights collaborative efforts between industry partners. Meanwhile, critical vulnerabilities in Claude Code have been exposed. Additionally, AI training data poisoning has become a growing concern.

The month of April saw a significant spike in cyber-attack activity, with ransomware expanding and attack volumes climbing after a brief moderation. Organizations experienced an average of 2,201 weekly cyber-attacks, representing a 10% increase month over month and an 8% increase year over year.

Top Articles

Vidar Stealer Campaign Evades EDR to Steal Credentials A new Vidar Stealer campaign is abusing trusted tools, multi-stage loaders, and heavy obfuscation to bypass EDR visibility and steal credentials from infected systems silently. This operation shows a clear shift toward “living-off-the-land” techniques and stealthy backdoor architectures that make traditional signature-based defenses almost useless. GBHackers

SAP Releases Patch for Critical SQL Injection Flaw in S/4HANA A severe vulnerability has struck the heart of enterprise resource planning systems this month, threatening organizations worldwide with potential data breaches. On May 12, 2026, the software giant released its monthly security patch update to address 15 newly discovered security flaws across its software ecosystem. GBHackers

Fake Invitation Phishing Is Becoming a Remote Access Problem for CISOs A new phishing campaign targeting U.S. organizations is exposing a dangerous security blind spot: attackers no longer need obvious malware to gain access. Sometimes all it takes is a fake invitation email, a CAPTCHA page, and a trusted remote management tool quietly installed inside the environment. CyberPress

UK fines water supplier $1.3M for exposing data of 664k customers The Information Commissioner’s Office has fined South Staffordshire Water Plc and parent company South Staffordshire Plc £963,900 ($1.3 million) over a cyberattack that exposed the personal data of 663,887 customers and employees. BleepingComputer

RubyGems Suspends New Signups After Hundreds of Malicious Packages Are Uploaded RubyGems, the standard package manager for the Ruby programming language, has temporarily paused account sign ups following what has been described as a “major malicious attack.” “We’re dealing with a major malicious attack on Ruby Gems right now,” Maciej Mensfeld said in a post on X. The Hacker News

AI Transparency: This newsletter uses AI to curate, rank, and summarize cybersecurity content from leading industry blogs. All articles link directly to original authors. Executive summaries are AI-generated based on article content. I curate the sources and deliver the digest—the original authors deserve the credit for their excellent work.