Description

Insufficient validation of untrusted input in Contextual Tasks in Google Chrome prior to 151.0.7922.109 allowed a remote attacker to perform privilege escalation via a crafted HTML page. (Chromium security severity: High)

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-08-06T22:16:59.363Z",
  "pubdate": "2026-08-06T22:16:59.363Z",
  "executiveSummary": "A high-severity vulnerability has been identified within Google Chrome prior to version 151.0.7922.109, specifically involving insufficient validation of untrusted input within Contextual Tasks. This security flaw enables a remote threat actor to achieve privilege escalation through the rendering of a maliciously crafted HTML page.\nThe vulnerability poses significant risk implications to browser security architecture, potentially allowing threat actors to bypass sandbox boundaries or execute unauthorized operations within the context of the application. The attack vector requires the user to navigate to or interact with a hostile web page controlled by the attacker.\nNo specialized authentication or elevated privileges are required on the victim system prior to exploitation, as the flaw is triggered remotely via standard web browsing vectors. Successful exploitation compromises the integrity and security boundary of the affected browser instance, leading to unauthorized capability escalation.\nOrganizations and end-users are strongly advised to apply the vendor-supplied security updates immediately to mitigate the risks associated with this vulnerability.",
  "technicalDetails": "The root cause of the vulnerability stems from inadequate sanitization and validation of untrusted input processed by the Contextual Tasks component within Google Chrome prior to version 151.0.7922.109. When the browser parses complex or malformed data structures supplied via web content, the lack of rigorous boundary checking and input verification allows aberrant data handling.\nThe attack vector relies on network exposure where a remote attacker hosts a crafted HTML page designed to interact with or trigger vulnerable routines inside the Contextual Tasks subsystem. When a victim accesses the malicious web page using an unpatched instance of Google Chrome, the browser processes the adversarial payload embedded within the HTML structure.\nThe step-by-step attack flow proceeds as follows: First, the remote attacker entices the user to load the crafted HTML page via standard web navigation or redirection. Second, the page leverages specific Document Object Model (DOM) interactions or automated triggers that interface with the Contextual Tasks feature. Third, the unvalidated input is passed into the vulnerable component, where parsing discrepancies or memory handling issues occur.\nBecause the input lacks proper validation, the malicious payload manipulates the internal state or execution flow of the Contextual Tasks component. This manipulation facilitates privilege escalation, allowing the attacker to bypass standard security boundaries enforced by the browser's architecture.\nThe affected component is the Contextual Tasks feature set within Google Chrome versions prior to 151.0.7922.109. Exploitation does not require prior authentication or local system privileges, relying entirely on the remote delivery of the crafted HTML payload to a vulnerable client instance over the network."
}