CVE-2026-121182
Description
An use after free flaw was found in the DOM 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 enforce Control Flow Integrity and Shadow Call Stack to validate indirect call targets and virtual table pointers, preventing control flow hijacking through freed DOM objects: upgrade to Google Chrome 157.0.8103.38+ (or the fixed Chromium builds), which resolves the use-after-free memory management flaw in the DOM component to prevent arbitrary code execution inside the renderer sandbox, closing crafted HTML page. Until patched, this is a concern on Users navigating to untrusted or compromised web pages across all supported platforms, so Restrict user navigation to trusted websites and isolate external web browsing sessions to prevent interaction with untrusted HTML content. As a compensating measure, Enable Address Space Layout Randomization to randomize process memory layout and hinder reliable heap exploitation, Enforce NX/XD non-executable memory protections to prevent code execution directly from DOM heap memory, Utilize full RELRO and PIE to enforce read-only relocation tables and obstruct code-reuse payloads, Run SELinux in enforcing mode to confine the Chromium renderer process to least-privilege domains, and Deploy EDR agents to monitor and detect anomalous process activity, shellcode injection, or unexpected child processes. These controls limit blast radius and contain exploitation, but they do not fix the underlying DOM use-after-free defect — apply the upstream patch to fully remediate.
Highest-impact CME: CME-301 SELinux (Enforcing Mode) (medium)
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory
The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.
Confidentiality
Technical Impact: Read Memory
Read operations on freed memory can sometimes leak sensitive information instead of causing a crash
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.
Frequently Asked Questions
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