Linux CVE-2026-64191

We need to analyze CVE-2026-64191. The provided data includes description, CVSS, EPSS, patch status, CPE, affected versions, references. I need to synthesize a comprehensive analysis, return JSON with specific fields. The vulnerability is in Linux kernel, specifically i2c-stub driver. It's a development/test tool, not built by default. Local user with access to /dev/i2c-* can cause out-of-bounds read/write via I2C_SMBUS ioctl with crafted block transfer. The fix rejects invalid lengths.

Now, let's fill each field carefully.

product_name: it's "Linux kernel" or more specifically "i2c-stub driver"? The instructions say "1-3 words ONLY. The specific product or service name affected." The vulnerability is in the Linux kernel's i2c-stub driver. But product name should be "Linux Kernel" because it's a driver within the kernel. However, maybe "i2c-stub driver" is too specific; "Linux Kernel" is the product. CPE is for linux:linux. The EUVD lists Linux various versions. So product_name = "Linux Kernel". I'll say "Linux Kernel" (2 words).

summary: 2-3 sentence plain-language synthesis. Must not start with "A vulnerability", etc. Start with impact verb and product. Explain what, who, what attacker can do. Use all data: it's a local out-of-bounds access in i2c-stub test driver, allowing local user to read/write beyond buffer, potentially leading to privilege escalation or information disclosure. Actively exploited? No KEV. EPSS is 0.17% very low. POC likely exists because description includes a reproducer with KASAN output. But no explicit "POC=YES". The description says "A local user with access to /dev/i2c-* can issue an I2C_SMBUS ioctl ... causing ... out-of-bounds". That's a POC description. So "publicly available exploit code exists". But note that the driver must be loaded with chip_addr parameter. So it's not widely deployed.

Summary: "Local privilege escalation in Linux Kernel's i2c-stub test driver allows any local user with access to /dev/i2c-* devices to trigger