Firefox 153 release notes for enterprise admins

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Firefox 153

Released 21 July 2026.

These changes apply to Firefox 153 and Firefox ESR 153 unless explicitly stated. Firefox ESR 153 is the new ESR - enterprise changes are no longer backported to Firefox ESR 140. Policies listed under Firefox ESR 153.0.0 became available to ESR admins for the first time in this release.

New in Firefox 153

• DisableRemoteSettingsAndAcceptSecurityConsequences: Disable Remote Settings updates and accept the resulting security consequences. Only use this policy when the consequences are fully understood.

Changes

• Containers: Updated for the new container color palette. Existing color names are migrated to the new names automatically.
• Cookies: Behavior and BehaviorPrivateBrowsing accept partition-foreign, the new name for the reject-tracker-and-partition-foreign cookie behavior. Configurations using the old name continue to work.
• ExtensionSettings: Control extension host permissions using runtime_allowed_hosts and runtime_blocked_hosts, and control which permissions extensions may request using allowed_permissions.
• Users can no longer change the host permissions of Manifest V3 extensions installed using force_installed.
• ExtensionSettings: force_installed and normal_installed extensions can be installed directly from addons.mozilla.org when install_url is omitted.
• Homepage: Added a NewTabOnRestore option to open the default start page or about:newtab after restoring a previous session.
• ManagedBookmarks: Bookmarklets using javascript: URLs are now supported.
• Automatically discovered printers are now listed after manually configured printers in the print destination list. (bug 1996569)
• Firefox installed from a macOS .pkg package can now update without prompting for administrator credentials. (bug 1812480)

Fixes

• AutoConfig can once again set the browser.startup.homepage preference to a data: URL, fixing a regression introduced in Firefox 152. (bug 2047962)
• DisableSecurityBypass: The Allow download button was still shown when SafeBrowsing was set to false. (bug 1894373)
• ExtensionSettings: Extensions that were no longer permitted by allowed_types were not removed or blocked when the setting changed. (bug 2008100)
• ExtensionSettings: Individual Windows registry REG_SZ values overrode the JSON policy configuration when both were present. (bug 2048696)
• FirefoxHome: The policy was not reflected correctly in the redesigned Settings. (bug 2048048)
• PasswordManagerEnabled: The policy did not disable the Passwords sidebar panel. (bug 2041232)
• PopupBlocking: The policy did not lock all of the pop-up permission controls. (bug 1888477)
• SanitizeOnShutdown: The policy now correctly locks the History settings when configured. (bug 1888451)
• The Bookmarks and History sidebars could not be opened while the sidebar was hidden and PasswordManagerEnabled was set to false. This regressed in Firefox 153.0 and was fixed in a later Firefox 153 release. (bug 2056857)

New in Firefox ESR 153.0.0

• AIControls: Configure AI controls.
• BrowserDataBackup: Disable backup or restore of profile data.
• DefaultSerialGuardSetting: Control use of the Web Serial API.
• DisableRemoteImprovements: Prevent Firefox from applying performance, stability, and feature changes between updates.
• DisableRemoteSettingsAndAcceptSecurityConsequences: Disable Remote Settings updates and accept the resulting security consequences.
• IPProtectionAvailable: Prevent the built-in VPN from being available to users.
• LocalNetworkAccess: Configure local network access security features.
• RelaunchRequired: Require Firefox to be relaunched within a given period and notify the user of the upcoming relaunch.
• SitePolicies: Fine-grained control over policies for specific sites.
• VisualSearchEnabled: Enable or disable visual search.
• XSLTEnabled: Enable or disable support for the XSLTProcessor JavaScript API and the XSLT processing instruction.