Week of May 18–24, 2026

Anthropic reports that about 50 Glasswing partners used Claude Mythos Preview to find more than ten thousand high- or critical-severity vulnerabilities, and that its own scan of over 1,000 open-source projects produced 6,202 model-estimated high/critical findings. Of 1,752 assessed, mostly by six independent firms, 90.6% were true positives; Anthropic estimates 530 high/critical bugs disclosed, of which 75 were patched, and says triage and patching capacity, not discovery, is the bottleneck.

Abdelnabi, Hicks, Rieck and Sadeghi argue that security evaluations of agents face three problems: agents can break the benchmark environment instead of solving the task, static benchmarks such as CyberGym and Cybench age as vulnerabilities are patched or leak, and stochastic behavior, agent-written code and external dependencies make single runs unreliable. They propose stronger environment isolation, canary tokens to detect cheating, continually updated or live benchmarks, reporting worst-case results and variance, and benchmark introspection, which they call a holistic first step.

Help Net Security reported that Linus Torvalds described the Linux kernel security list as almost entirely unmanageable because of heavily duplicated AI-assisted reports, and that GitHub tightened its bug bounty submission requirements, with a GitHub engineer saying some programs elsewhere had shut down. The article also notes that curl ended bounty payments after a surge of low-quality AI reports.

The NSA's Artificial Intelligence Security Center released a cybersecurity information sheet on the Model Context Protocol, warning that adoption has outpaced safeguards. It recommends vetting MCP tools, least-privilege access and isolation, validating outputs where one model's output feeds another, and detailed logging integrated with security monitoring, and it lists poor approval workflows among the risks.