CVE-2026-85046, Google Chrome: V8 type confusion exploited in the wild via a crafted HTML page
Google ships an emergency Chrome update for a V8 flaw it says is already being exploited
Defender actions
- Confirm Chrome auto-update policy is active fleet-wide (or push 152.0.7977.82+ via enterprise management) on every Windows, Mac and Linux endpoint, and check any Chromium-based browser in use (Edge, Brave, Vivaldi) for its own equivalent fix, since Google states an exploit for CVE-2026-85046 already exists in the wild.
Analysis
Google's Chrome 152.0.7977.82/.83 Stable release (2026-09-03) fixes 12 security bugs, headed by CVE-2026-85046, a type confusion in the V8 JavaScript engine (Google Chrome Releases, 2026-09-03). CISA's KEV record describes it as letting a remote attacker execute arbitrary code inside the sandbox via a crafted HTML page and classes it CWE-843 (CISA KEV catalog, 2026-09-04). Google's release notes state that "Google is aware that an exploit for CVE-2026-85046 exists in the wild", and the bug (Chromium issue 542403045) was reported by external researcher Salvatore Gulizia ("Serotav") on 2026-08-04 (Google Chrome Releases, 2026-09-03). Google publishes no numeric CVSS score.
Code run through the type confusion stays inside the renderer sandbox (CISA KEV catalog, 2026-09-04), so the flaw is not a sandbox escape by itself and full host compromise needs further bugs. Proofpoint has since documented the BlueMoon exploit kit, used by several state-aligned threat actors, which chains CVE-2026-85046 with a V8 sandbox escape and a Windows kernel privilege-escalation flaw (Proofpoint, 2026-09-08). The remaining 11 fixes in the same release (9 High- and 2 Medium-severity issues across V8, Compositing, WebGL, Skia, DevTools, CacheStorage, CrashReporting, Network, Mobile and the Transactions Platform, most found by Google's own security team) carry no exploitation report from Google (Google Chrome Releases, 2026-09-03).
Cited evidence
Google is aware that an exploit for CVE-2026-85046 exists in the wild.
Updates1
CISA's KEV record, not Google's release note, is the source for the crafted-HTML-page vector, code execution inside the sandbox and the CWE-843 class (CISA KEV catalog, 2026-09-04). The earlier text gave CISA-ADP's CVSS 8.8 score, which comes from CISA's enrichment of the CVE record rather than from a cited advisory, so no score is shown. It also called the flaw a sandbox-escape primitive. Code run through it stays inside the renderer sandbox (CISA KEV catalog, 2026-09-04), so it is not a sandbox escape. The earlier statement that no source described chaining no longer holds: Proofpoint documents the BlueMoon exploit kit chaining CVE-2026-85046 with a V8 sandbox escape and a Windows kernel privilege-escalation flaw (Proofpoint, 2026-09-08). Google lists CVE-2026-85043 as incomplete cleanup in Network (Google Chrome Releases, 2026-09-03). The earlier detection guidance assumed Google was withholding exploit specifics. Proofpoint has since described the chain's post-exploitation step, in which the Chrome browser process runs curl to download and execute a file (Proofpoint, 2026-09-08).
Sources3
Revision history
- Published 2026-09-04T0410Z-intel
- Correction 2026-09-30T0639Z-audit
The main text cited Google's release note for the crafted-HTML-page vector, sandboxed code execution and CWE-843, which come from CISA's KEV record, and carried CISA-ADP's CVSS 8.8 score from CISA's enrichment of the CVE record rather than from a cited advisory, so no score is shown. It also called the flaw a sandbox-escape primitive although code run through it stays inside the renderer sandbox, and said no source described chaining, while Proofpoint has since documented the BlueMoon kit chaining it with a sandbox escape and a Windows privilege-escalation flaw. CVE-2026-85043 is Google's incomplete cleanup in Network, not an information disclosure. Detection now covers the Chrome browser process running curl to download and execute a file, which Proofpoint documents for the BlueMoon chain.
Changed: sources cves sourcing_note evidence body references verification classification
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