Check Point found Claude Code flaws allowing code execution and Anthropic API key theft from a malicious repository

Microsoft disclosed two vulnerabilities that turn prompt injection into host compromise in its Semantic Kernel agent framework, which has over 27,000 GitHub stars. CVE-2026-26030 affects the Python package before 1.39.4: the default in-memory vector store filter is a Python lambda executed with eval() on unsanitized model-controlled input, so an attacker could escape the template string, traverse Python's class hierarchy, bypass the AST blocklist validator and run arbitrary commands, demonstrated by launching calc.exe from a single prompt injection. CVE-2026-25592 affects the .NET SDK before 1.71.0: DownloadFileAsync was accidentally marked with a [KernelFunction] attribute, exposing it to the model with an entirely AI-controlled, unvalidated local file path, allowing writes to locations such as the Windows Startup folder and thus sandbox escape.

Varonis Threat Labs disclosed CVE-2026-42824, a critical flaw in Microsoft 365 Copilot Enterprise Search. Clicking a single crafted link chained three bugs: injection of the URL parameter into the prompt, a rendering race condition, and abuse of Content Security Policy allowlisting to exfiltrate data through Bing's infrastructure. The attack could reach emails and calendar details, indexed SharePoint and OneDrive files, one-time and MFA codes, password-reset links, meeting notes and salary data. Because Copilot Enterprise is a managed service, tenant admins could not patch it themselves; Microsoft mitigated the flaw on its backend.

Pillar Security disclosed CVE-2026-22708 in Cursor. In Auto-Run Mode with an allowlist enabled, shell built-ins such as export, typeset, declare, readonly, unset and local were implicitly trusted by Cursor's server-side evaluator and executed without appearing in the allowlist or requiring approval, because they run inside the shell session rather than as separate binaries. An attacker delivering indirect prompt injection could silently poison environment variables and then trigger malicious code through trusted developer tools, producing both zero-click and one-click remote code execution. Pillar reported it in August 2025, Cursor acknowledged it as a systemic issue in September 2025, and the fix shipped in version 2.3 in January 2026, which now requires explicit approval for any command the parser cannot classify.