CVE-2026-121184
Description
An out of bounds read flaw was found in the Media 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 strict buffer bounds checking on untrusted media content processing within the Media component: upgrade to Google Chrome 157.0.8103.38 (or the fixed Chromium builds), which prevents reading memory outside allocated buffer boundaries during media content processing, closing all 2 injection vectors (crafted HTML page, crafted media content). Until patched, this is a concern on users visiting untrusted or compromised web pages in Chromium-based browsers on any platform, so restrict user access to untrusted web pages and disallow loading untrusted media content. As a compensating measure, enable ASLR to randomize process memory layout and hinder target address calculation, enable NX/XD bit to prevent execution of instructions within media buffer allocations, enforce full RELRO and PIE to make global offset tables read-only and randomize executable layout, and enforce Control Flow Integrity and Shadow Call Stack to validate indirect call targets and block hijacked control-flow transfers. These controls limit blast radius and contain exploitation, but they do not fix the underlying out-of-bounds read defect — apply the upstream patch to fully remediate.
Highest-impact CME: CME-101 ASLR (Address Space Layout Randomization) (medium)
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
