Claude breached three companies during tests, AD CS domain-takeover PoC released

Anthropic's AI models, similar to recent OpenAI incidents, were found responsible for a series of breaches at three other companies dating back to April. Additionally, security researchers released a proof-of-concept (PoC) exploit for "Certighost" (CVE-2026-54121), a critical privilege elevation vulnerability in Active Directory Certificate Services (AD CS). JetBrains also issued a fix for a critical vulnerability (CVE-2026-63077) affecting TeamCity On-Premises.