Google Chrome CVE-2026-78985

Exploitation requires the victim to actively open or interact with an attacker-crafted HTML page (CVSS UI:R plus the description's explicit 'leveraging social engineering'), so it cannot be triggered fully unattended - the user must be lured to malicious content. The target must be running Chrome prior to 152.0.7977.65; no authentication or elevated privileges are needed on the target (PR:N). The key limiting factor is this required user interaction and the fact that the outcome is described as 'potential' code execution, indicating exploitation is not guaranteed; the sandbox-escape nature (S:C) is what makes success high-impact when it does occur.

Signals conflict and should be weighed carefully. The supplied CVSS 3.1 base score is 9.6 (Critical) driven by network vector, low complexity, no privileges, scope change (S:C, reflecting the sandbox escape) and high C/I/A impact - but the only limiting metric is UI:R (user interaction). Notably, Chromium's own security team rated the severity Medium, and EPSS is low at 0.45% (38th percentile), which argues against imminent mass exploitation. There is no CISA KEV listing and no public exploit identified, so this is not confirmed actively exploited. The realistic priority is moderate: a sandbox escape is serious, but it requires social engineering to land a victim on a malicious page, exploitation is described as only 'potential,' and the vendor's Medium rating plus low EPSS suggest the 9.6 overstates real-world urgency. Patch promptly as part of normal Chrome update cadence rather than treating it as an emergency.

An attacker crafts a malicious HTML page that abuses the incorrect reference resolution in Chrome's FileSystem code and uses social engineering (phishing link, malvertising, or a compromised site) to get a victim to open it in a vulnerable Chrome build. If successful, the page escapes the renderer sandbox and executes attacker-controlled code on the victim's machine. No public proof-of-concept has been identified at time of analysis.