CVE-2026-111497 Google Brotli: memory-safety flaw
In plain words: The program mishandles the memory it uses to keep track of data. A specially made input can scramble that memory. Usually lets an attacker crash the program or run their own code with its permissions.
Confirmed exploited by CISA on · US federal patch deadline Nov 10, 2026
What to do
- Install Google's security update for Brotli. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- Google Brotli Unchecked Return Value Vulnerability
- Product
- Google Brotli
- CISA description
- Google Brotli contains an unchecked return value vulnerability that allows a remote unauthenticated attacker to corrupt adjacent decoder state memory, disclose sensitive memory contents, cause a denial of service, or potentially execute arbitrary code using a crafted Brotli-compressed stream.
- Type of flaw
- Memory-safety flaw (CWE-252, CWE-787)
- Confirmed exploited
- Oct 27, 2026
- US federal patch deadline
- Nov 10, 2026
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Answering about CVE-2026-111497 ·
Questions about CVE-2026-111497
Is CVE-2026-111497 being exploited?
Yes. CISA added CVE-2026-111497 to its Known Exploited Vulnerabilities catalog on Oct 27, 2026, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2026-111497?
Install Google's security update for Brotli. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2026-111497?
Only if you use Google Brotli. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.