Google fixed the first actively exploited Chrome zero

Out of bounds write in V8 in Google Chrome prior to 120.0.6099.224 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: High)

Google Chrome's V8 JavaScript engine, in versions prior to 120.0.6099.224, contains an out-of-bounds memory access flaw (CWE-787 out-of-bounds write / CWE-125 out-of-bounds read) that is triggered when a user visits a specially crafted HTML page. A remote attacker who lures a victim to such a page can potentially corrupt the heap and execute code in the context of the browser. Successful exploitation could lead to exposure of sensitive information, data tampering, or denial of service (CVSS 3.1: 8.8 High; user interaction is required). Anyone running a vulnerable Chrome/Chromium build is affected, including downstream products that embed V8, such as Fedora's Chromium/Chrome packages and Couchbase Server. The flaw is being actively exploited in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2024-01-17, and news coverage describes it as one of Google's actively exploited Chrome zero-days patched in January 2024.

Do: Update Google Chrome to 120.0.6099.224 or later (and restart the browser so the new version is fully loaded); verify fleet versions via Chrome's version reporting if managing enterprise deployments. Fedora users should install the updated chromium/chrome packages via the distribution's update channel, and Couchbase Server operators should apply the vendor's guidance. Because the flaw is on CISA's KEV catalog, federal and other regulated environments are required to apply vendor mitigations promptly; the only effective mitigation is patching, as no public PoC or alternate workaround is documented.