It released new versions for .NET 8, 9, 10, and .NET 11 to patch against the Brotli bug, following similar updates from Node.js, Python, and other projects. Senior program manager Rahul Bhandari said in the October 25 release that the buffer overflow vulnerability in Brotli, tracked as CVE-2026-111497 and rated 8.1 under CVSS v3.1 in Microsoft's advisory, could allow an unauthenticated attacker to read or corrupt process memory, potentially resulting in information disclosure, denial of service, or elevation of privilege.
Microsoft’s own advisory for the vulnerability, which some are referring to as Broccoli2Shell or Node2Shell, confirms that while experts have cobbled working exploits together, there is nothing to suggest that criminals are using them in successful attacks. Still, its exploitability assessment reads: “Exploitation More Likely.”
