CVE-2026-111497: Google Brotli Unchecked Return Value Vulnerability
Summary
A critical vulnerability, CVE-2026-111497, has been identified in Google Brotli, allowing remote attackers to corrupt memory, disclose sensitive information, or execute code via crafted streams. CISA has mandated actions for federal agencies, including applying vendor-provided mitigations and adhering to specific patching deadlines.
IFF Assessment
This vulnerability allows for memory corruption, information disclosure, and potential code execution, posing a significant risk to systems.
Severity
The CVSS score of 9.8 reflects the high severity of this vulnerability, considering its attack vector (network), complexity (low), privileges required (none), user interaction (none), and the significant impacts on confidentiality, integrity, and availability, including potential code execution.
CISA KEV: Listed as actively exploited. Federal patch due: November 10, 2026. Known ransomware use: Unknown.
Defender Context
This vulnerability in Google Brotli presents a severe risk, as it can lead to memory corruption, data disclosure, and even remote code execution. Defenders must prioritize applying vendor-provided patches and mitigations immediately, especially for internet-facing systems, and ensure compliance with CISA's guidance on risk-based patching.