Specifies whether SharedArrayBuffers can be used in a non cross-origin-isolated context
This value controls whether websites in Microsoft Edge may use `SharedArrayBuffer` outside a cross-origin-isolated context.
since 0.9.8.11
Purpose
Show registry keys (1)
HKLM\Software\Policies\Microsoft\Edge\SharedArrayBufferUnrestrictedAccessAllowed
This value controls whether websites in Microsoft Edge may use SharedArrayBuffer outside a cross-origin-isolated context. SharedArrayBuffer provides web applications with a binary memory region that can be accessed by multiple execution contexts.
A DWORD value of 0 disallows unrestricted access. Websites may therefore use SharedArrayBuffer only when they are cross-origin isolated. The same restriction applies when the policy is not configured. A value of 1 would remove this requirement.
Notes
Security
The value preserves Microsoft Edge's isolation requirement for SharedArrayBuffer. This requirement is associated with memory-access vulnerabilities affecting modern processors. Setting the value to 0 prevents websites from using the API without the additional protection provided by cross-origin isolation.
This setting does not remediate processor vulnerabilities or eliminate every risk posed by untrusted web content. Its specific effect is to prevent the relaxation of the access conditions for SharedArrayBuffer that this policy can otherwise permit.
Possible side effects
Web applications that depend on SharedArrayBuffer but do not establish cross-origin isolation cannot use the API. Depending on the application, affected features may become unavailable, fall back to a slower implementation, or encounter compatibility problems. Properly isolated sites can continue to use SharedArrayBuffer.
Notes
Microsoft supports this policy on Windows beginning with Microsoft Edge version 92. The policy has a Boolean data type, represented in the Windows registry as REG_DWORD. It does not support dynamic policy refresh, so a browser restart is required before a changed value takes effect.