Exploited vulnerability · CISA KEV

Is CVE-2026-111497 exploited? Yes: in CISA KEV since 27 Oct 2026

Gociux · Google Brotli · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2026-111497, Google Brotli Unchecked Return Value Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 27 Oct 2026, 5 days after it was published. It affects Google Brotli. If you run it, CISA's required action is: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

What it is

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.

What to do

1. Check whether you run it. Look for Brotli in your asset inventory, including appliances and cloud images. Stack check lists every exploited Google CVE at once.
2. Apply the fix. Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 22 Oct 2026.
4. Get told next time. Email alerts when CISA adds a CVE for Google.

References

• nvd.nist.gov/vuln/detail/CVE-2026-111497

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in October 2026 · Google scorecard · act-now radar.