Skip to content

CVE-2025-21172

CVE

Threat entity extracted from intelligence sources

Frequency
1
occurrences
First Seen
October 27, 2026
Last Seen
October 27, 2026
API
Exploited in Wild
—
Ransomware Use
—
Public Exploits
—
Attack Vector
—

Vulnerability Overview

Exploitation Activity

Exploitation Intelligence

Critical Brotli Vulnerability in .NET Requires Immediate Patching78.0

Microsoft released an emergency out-of-band patch on October 26, 2026, for CVE-2026-111497, a critical out-of-bounds write vulnerability in the Brotli decompression library affecting .NET versions 8, 9, 10, and 11 RC3. This flaw allows unauthenticated remote attackers to exploit affected application...

Public Exploits

Checking GitHub for proof-of-concept code…

CVE Details

Related Entities

Zero-day ExploitCVE-2026-111497CWE-787 - Out-of-bounds WriteHealthcareT1059 - Command and Scripting InterpreterT1105 - Ingress Tool TransferT1190 - Exploit Public-Facing ApplicationT1203 - Exploitation for Client ExecutionT1499 - Endpoint Denial of ServiceASP.NET CoreBrotliHTTP/2