CVE-2026-118331
Description
An improper input validation flaw was found in the FileAPI component of the Chromium browser.
Upstream bug(s):
Statement
Red Hat Product Security rates the severity of this flaw as determined by the Google Chrome Security Advisory.
Mitigation
--- CME Mitigation Guidance (2026-11-03) ---
Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.
The highest-value action is to enforce strict input validation and confinement on all untrusted parameters and path structures passed to FileAPI handlers: upgrade to Google Chrome 156.0.8078.73+ (or the fixed Chromium builds), which validates untrusted input parameters in the FileAPI component before processing to prevent sandboxed code execution, closing crafted HTML page. Until patched, this is a concern on deployments across all platforms where users browse untrusted web content, so restrict user browsing to trusted sites and avoid loading untrusted HTML documents or links from remote networks. As a compensating measure, restrict FileAPI virtual filesystem operations and isolate file path access within the browser designated sandbox directory boundaries, canonicalize untrusted file descriptors, paths, and type identifiers supplied via the HTML page before processing by FileAPI handlers, and enforce strict allowlist-based validation on parameters and input structures passed into the browser FileAPI. These controls limit blast radius and contain exploitation, but they do not fix the underlying improper input validation defect — apply the upstream patch to fully remediate.
Highest-impact CME: CME-1303 Application-Level Filesystem Access Confinement (medium)
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
An attacker could provide unexpected values and cause a program crash or arbitrary control of resource allocation, leading to excessive consumption of resources such as memory and CPU.
Confidentiality
Technical Impact: Read Memory; Read Files or Directories
An attacker could read confidential data if they are able to control resource references.
Integrity,Confidentiality,Availability
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
An attacker could use malicious input to modify data or possibly alter control flow in unexpected ways, including arbitrary command execution.
Frequently Asked Questions
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