CVE-2026-87491
Published 2026-09-09 · Updated 2026-09-21 · Source chrome-cve-admin@google.com
Summary
CVE-2026-87491 is a high-severity (CVSS 8.8) vulnerability in Google Chromium V8. CISA added it to the Known Exploited Vulnerabilities catalog on September 9, 2026, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by September 23, 2026. CISA does not currently list it as used in ransomware campaigns. Google has 75 vulnerabilities in the KEV catalog, 0 of them linked to ransomware.
All 75 known-exploited Google vulnerabilities →Description
Out of bounds write in V8 in Google Chrome prior to 153.0.8010.36 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: Medium)
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CISA Known-Exploited Vulnerability
Product: Google — Chromium V8
Name: Google Chromium V8 Out of Bounds Write Vulnerability
Date added: 2026-09-09 · Due: 2026-09-23
Required action: 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.