Google Chrome EUVD-2026-89224

Exploitation requires the victim to run a vulnerable Chrome desktop build (before 154.0.8037.57) and to actively visit or interact with attacker-controlled web content (UI:R). No authentication is required (PR:N), but the trigger has high attack complexity (AC:H), implying the attacker must win a race or satisfy specific timing/memory-state conditions rather than firing a single deterministic request. The flaw is an incorrect-authorization (CWE-863) security-boundary bypass whose success crosses the sandbox scope (S:C). Limiting factors: mandatory user interaction, AC:H reliability constraints, and the availability of a vendor patch all reduce realistic exploitation likelihood; there is no default-on server-side exposure since the client must browse to malicious content.

This is a real high-priority issue but its exploitability is bounded by attack complexity. The CVSS 3.1 vector (AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H, 8.3) describes a network-reachable, unauthenticated flaw that nonetheless requires both user interaction (visiting a malicious page) and a high-complexity trigger (AC:H - likely timing, grooming, or a race), and produces a scope change (S:C) with full confidentiality/integrity/availability impact. In Chrome terms, CWE-863 (Incorrect Authorization) combined with S:C and C:H/I:H/A:H points to a security-policy/permission-enforcement bypass that escapes the renderer sandbox - an RCE-class outcome rather than a simple 'authentication bypass.' Signals are mixed on urgency: no EPSS score, no CISA KEV listing, and no public POC are present in the input, so there is no evidence of active exploitation or automated weaponization - this is not confirmed in-the-wild. The AC:H requirement further lowers the odds of reliable mass exploitation compared with the AC:L siblings in the same Chrome release. A patch is available from the vendor. Net: prioritize patching because of Chrome's ubiquity and the full-impact scope change, but recognize the raw 8.3 overstates near-term real-world risk absent EPSS/KEV/POC signals and given AC:H. Note: the input tag 'Authentication Bypass' understates the impact - the CVSS shows full code-execution-class C/I/A, not a mere auth bypass.

An attacker hosts a malicious web page and lures a Chrome user (before 154.0.8037.57) into visiting it, e.g. via phishing or a malvertising redirect. The page exercises the incorrect-authorization flaw under carefully timed conditions (AC:H) to bypass a browser security boundary, cross the sandbox scope (S:C), and gain code execution or full data access on the host. No public exploit code is identified at time of analysis.