Published on October 30, 2026 at 1:02 PM

CVE-2026-111497 is a critical vulnerability affecting the Brotli decoder used in Google Brotli versions 1.0.3 through 1.2.0. This vulnerability is significant due to its potential to allow remote code execution, which can have severe implications for affected systems.

What the vulnerability is

The vulnerability is a buffer overflow in the Brotli decoder, specifically located in the c/dec/decode.c file. This flaw allows a remote unauthenticated attacker to exploit the system by corrupting adjacent decoder state memory. The exploitation can lead to the disclosure of sensitive memory contents, cause a denial of service, or potentially execute arbitrary code.

Impact

The primary impact of CVE-2026-111497 is the potential for remote code execution. An attacker could use a crafted Brotli-compressed stream to achieve this, which could compromise the integrity and confidentiality of the affected systems. Additionally, the vulnerability could lead to a denial of service, disrupting normal operations.

Affected systems

Affected systems have not been publicly disclosed at the time of writing. However, it is known that Google Brotli versions 1.0.3 through 1.2.0 are vulnerable.

Mitigation

To mitigate this vulnerability, users should update their Brotli libraries or binaries to the latest available versions. Specifically, updating to version 1.0.10, 1.1.1, 1.2.1, or any later version is recommended. This update addresses the buffer overflow issue and secures the system against potential exploits.

Continuous scanning and timely updates are crucial in identifying and mitigating vulnerabilities like CVE-2026-111497 before they can be exploited by attackers. Ensuring that systems are running the latest software versions is a fundamental step in maintaining security.