CVE-2026-121208
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 control flow integrity on indirect calls and returns within Chromium media processing to prevent arbitrary code execution inside the renderer sandbox: upgrade to Google Chrome 157.0.8103.38+ (or the fixed Chromium builds), which validates memory bounds during media processing in the Media component to prevent out-of-bounds reads, closing all 2 injection vectors (crafted HTML page, crafted media content). Until patched, this is a concern on Users and desktop environments processing untrusted HTML pages or media streams in Chromium, so Restrict user web navigation to trusted origins and prevent loading unvetted external HTML pages or media payloads. As a compensating measure, Ensure system-wide address space layout randomization is enforced to hinder reliable pointer calculations from memory disclosures, Enforce non-executable memory pages across heap and data allocations to prevent executing shellcode in media buffers, and Compile binaries with position-independent executable code and full read-only relocations to protect the Global Offset Table. 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-113 Control Flow Integrity (CFI / Shadow Call Stack) (high)
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.
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