CVE-2026-121078
Description
A type confusion flaw was found in the V8 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 (2026-11-04) ---
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 disable JIT compilation using the --jitless flag or disable JavaScript execution within the V8 engine for untrusted origins: upgrade to Google Chrome 157.0.8103.38 (or the fixed Chromium builds), which corrects the type confusion flaw in the V8 JavaScript engine, closing all 2 injection vectors (crafted HTML page, malicious JavaScript execution). Until patched, this is a concern on all platforms running Chromium or Google Chrome, so avoid navigating to untrusted HTML pages and restrict JavaScript execution or run browsers with the --jitless flag to prevent triggering JIT-related type confusion. As a compensating measure, enforce Control Flow Integrity to constrain indirect branch targets and restrict execution flow hijacking following type confusion and deploy endpoint detection and response agents to detect post-exploitation behavior and anomalous processes spawned inside or outside the browser sandbox. These controls limit blast radius and contain exploitation, but they do not fix the underlying type confusion defect — apply the upstream patch to fully remediate.
Highest-impact CME: CME-1309 Script Engine Restriction (Sandbox / Disable) (high)
Understanding the Weakness (CWE)
Other
Technical Impact: Varies by Context
When the product accesses the resource using an incompatible type, this could trigger logical errors because the resource does not have expected properties.
Availability,Integrity,Confidentiality
Technical Impact: Read Memory; Modify Memory; Execute Unauthorized Code or Commands; DoS: Crash, Exit, or Restart
If a memory buffer is accessed using an incompatible type, and the allocated buffer is smaller than the type that the code is attempting to access, then an attacker could read or write memory outside the bounds of the buffer, leading to a crash or possibly code execution.
Frequently Asked Questions
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