# Mullvad Browser changelog

> A privacy-focused browser developed with the Tor Project, minimizing fingerprinting without the Tor network.

- Vendor: Mullvad VPN
- Category: Browsers
- Platforms: Desktop
- Official site: https://mullvad.net/browser
- Tracked by: What's New (https://whatsnew.fyi/product/mullvad-browser)
- Harvested from: GitHub (mullvad/mullvad-browser)
- Entries below: 10 (newest first)

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

## Releases

### 15.0.19

- Date: 2026-07-24
- Version: 15.0.19
- Original notes: https://github.com/mullvad/mullvad-browser/releases/tag/15.0.19
- Permalink: https://whatsnew.fyi/product/mullvad-browser/releases/15.0.19
- Labels: Platforms: Desktop

- **changed** — Updated Firefox to 140.13.0esr
- **changed** — Updated NoScript to 13.6.31.1984
- **fixed** — Backport Security Fixes from Firefox 153

* All Platforms
   * Updated Firefox to 140.13.0esr
   * Updated NoScript to 13.6.31.1984
   * Bug 558: Rebase Mullvad Browser stable onto 140.13.0esr [mullvad-browser]
   * Bug 45124: Backport Security Fixes from Firefox 153 [tor-browser]
##### Build System
   * All Platforms
     * Bug 41838: Update personal_access_tokens URL in tools/fetch_changelogs.py [tor-browser-build]
   * Windows
     * Bug 41819: Fix windows-rs URL in projects/firefox/config [tor-browser-build]

### 16.0a9

- Date: 2026-07-24
- Version: 16.0a9
- Original notes: https://github.com/mullvad/mullvad-browser/releases/tag/16.0a9
- Permalink: https://whatsnew.fyi/product/mullvad-browser/releases/16.0a9
- Labels: Pre-release; Platforms: Desktop

- **changed** — Updated Firefox to 153.0esr
- **changed** — Updated NoScript to 13.6.30.90201984
- **changed** — Updated uBlock Origin to 1.72.2
- **fixed** — Fixed about:preferences being broken in 153 nightlies
- **removed** — Removed translate action from urlbar
- **removed** — Removed the lock on pdfjs.disable
- **changed** — Disabled the settings redesign until ready
- **fixed** — Fixed security level using an unsafe getBoolPref
- **fixed** — Fixed undeclared identifier 'XRE_EXECUTABLE_FILE' in nsAppFileLocationProvider.cpp
- **fixed** — Fixed wchar_t to char conversion in desktop_capture_utils.cc on Windows
- **fixed** — Fixed artifact generation failing due to missing .DS_Store in branding directories on macOS

* All Platforms
   * Updated Firefox to 153.0esr
   * Updated NoScript to 13.6.30.90201984
   * Updated uBlock Origin to 1.72.2
   * Bug 559: about:preferences is broken in 153 nightlies [mullvad-browser]
   * Bug 561: Rebase Mullvad Browser onto 153.0esr [mullvad-browser]
   * Bug 44439: Remove translate action from urlbar [tor-browser]
   * Bug 44811: Remove the lock on pdfjs.disable. [tor-browser]
   * Bug 45110: Disable the settings redesign until ready for us [tor-browser]
   * Bug 45131: Security level is using an unsafe getBoolPref [tor-browser]
   * Bug 45132: nsAppFileLocationProvider.cpp: use of undeclared identifier 'XRE_EXECUTABLE_FILE' [tor-browser]
 * Windows
   * Bug 555: Fix our wchar_t to char conversion in desktop_capture_utils.cc [mullvad-browser]
 * macOS
   * Bug 45108: Artifact generation fails due to missing .DS_Store in the branding directories [tor-browser]
##### Build System
   * All Platforms
     * Bug 41838: Update personal_access_tokens URL in tools/fetch_changelogs.py [tor-browser-build]
   * Windows
     * Bug 41819: Fix windows-rs URL in projects/firefox/config [tor-browser-build]

### 15.0.18

- Date: 2026-07-14
- Version: 15.0.18
- Original notes: https://github.com/mullvad/mullvad-browser/releases/tag/15.0.18
- Permalink: https://whatsnew.fyi/product/mullvad-browser/releases/15.0.18
- Labels: Platforms: Desktop

- **changed** — Updated NoScript to 13.6.30.1984
- **changed** — Updated uBlock Origin to 1.72.2
- **changed** — Cherry-pick latest firefox/esr140 commits on 140.12.0esr

* All Platforms
   * Updated NoScript to 13.6.30.1984
   * Updated uBlock Origin to 1.72.2
   * Bug 45111: Cherry-pick latest firefox/esr140 commits on 140.12.0esr [tor-browser]
##### Build System
   * All Platforms
     * Bug 41821: Update gpg subkeys for boklm [tor-browser-build]
     * Bug 41827: Update morgan's keychain with renewed key [tor-browser-build]

### 16.0a8

- Date: 2026-07-02
- Version: 16.0a8
- Original notes: https://github.com/mullvad/mullvad-browser/releases/tag/16.0a8
- Permalink: https://whatsnew.fyi/product/mullvad-browser/releases/16.0a8
- Labels: Pre-release; Platforms: Desktop

- **changed** — Updated Firefox to 152.0a1
- **changed** — Updated NoScript to 13.6.25.90301984
- **fixed** — Make sure desktop IP Protection is disabled on desktop
- **removed** — Drop browser.display.use_system_colors from preference list
- **fixed** — Remove unused pref privacy.partition.network_state
- **changed** — Use context-fill for about-wordmark.svg
- **changed** — Switch colours in letterboxing setting icons to match the tab-alignment icons
- **fixed** — Several errors about EngineProcess.sys.mjs in 152
- **fixed** — Wrong letterboxing background in 152
- **fixed** — Resistfingerprinting not available in appearance.mjs in 152
- **fixed** — ReportBrokenSite startup error in 152
- **fixed** — Potential runtime errors in the search service when changing JS status
- **fixed** — Re-add missing changes to settings after 151/152 rebase
- **security** — Cross-site oracle via worklet rejection error in Safer Mode
- **changed** — Disable XSLT for 16.0
- **fixed** — Error in about:preferences due to ipprotection missing
- **fixed** — ABI::Windows::Graphics::Capture::IID_IGraphicsCaptureSession2 is used again in wgc_capture_session.cc on Windows
- **fixed** — Bundled fonts are broken on macOS when the GPU process is enabled
- **fixed** — Crash in libfontconfig.so.1 after users upgraded to fontconfig 2.18.0 on Linux

* All Platforms
   * Updated Firefox to 152.0a1
   * Updated NoScript to 13.6.25.90301984
   * Bug 44528: Make sure desktop IP Protection is disabled on desktop [tor-browser]
   * Bug 44795: Revert BB 27604 patch as not needed anymore [tor-browser]
   * Bug 44857: Drop `browser.display.use_system_colors` from our preference list [tor-browser]
   * Bug 44896: Review Mozilla 2030929: Remove unused pref privacy.partition.network_state [tor-browser]
   * Bug 44955: Use `context-fill` for `about-wordmark.svg` [tor-browser]
   * Bug 44956: Switch colours in letterboxing setting icons to match the tab-alignment icons [tor-browser]
   * Bug 45016: Several errors about EngineProcess.sys.mjs in 152 [tor-browser]
   * Bug 45017: Wrong letterboxing background in 152 [tor-browser]
   * Bug 45018: resistfingerprinting not available in appearance.mjs in 152 [tor-browser]
   * Bug 45019: ReportBrokenSite startup error in 152 [tor-browser]
   * Bug 45037: Potential runtime errors in the search service when changing JS status [tor-browser]
   * Bug 45043: Re-add missing changes to settings after 151/152 rebase [tor-browser]
   * Bug 45047: Cross-site oracle via worklet rejection error in Safer Mode [tor-browser]
   * Bug 45072: Disable XSLT already for 16.0 [tor-browser]
   * Bug 45083: Error in about:preferences due to ipprotection missing [tor-browser]
 * Windows
   * Bug 552: ABI::Windows::Graphics::Capture::IID_IGraphicsCaptureSession2 is used again in wgc_capture_session.cc [mullvad-browser]
 * macOS
   * Bug 44728: Bundled fonts are broken on macOS when the GPU process is enabled [tor-browser]
 * Linux
   * Bug 45048: Backport Bugzilla 2041887: Crash in [@ libfontconfig.so.1] after users upgraded to fontconfig 2.18.0 [tor-browser]
##### Build System
   * All Platforms
     * Bug 41802: Remove the tor daemon requirement for signing [tor-browser-build]
     * Bug 41809: Update toolchains for Firefox 152 [tor-browser-build]
     * Bug 41813: Disable build artifacts in `make generate_gradle_dependencies_list-geckoview` [tor-browser-build]
     * Bug 41821: Update gpg subkeys for boklm [tor-browser-build]
     * Bug 41823: Add versions information to the toolchain list update [tor-browser-build]
     * Bug 41827: Update morgan's keychain with renewed key [tor-browser-build]

### 15.0.16

- Date: 2026-06-18
- Version: 15.0.16
- Original notes: https://github.com/mullvad/mullvad-browser/releases/tag/15.0.16
- Permalink: https://whatsnew.fyi/product/mullvad-browser/releases/15.0.16
- Labels: Platforms: Desktop

- **changed** — Updated Firefox to 140.12.0esr
- **changed** — Updated NoScript to 13.6.24.1984
- **changed** — Updated uBlock Origin to 1.71.0
- **fixed** — Fixed NS 13.6.19.902 DocStartInjection regression
- **security** — Backported security fixes from Firefox 152

* All Platforms
   * Updated Firefox to 140.12.0esr
   * Updated NoScript to 13.6.24.1984
   * Updated uBlock Origin to 1.71.0
   * Bug 553: Rebase Mullvad Browser stable onto 140.12.0esr [mullvad-browser]
   * Bug 45044: NS 13.6.19.902 DocStartInjection regressed [tor-browser]
   * Bug 45054: Backport Security Fixes from Firefox 152 [tor-browser]
##### Build System
   * All Platforms
     * Bug 41802: Remove the tor daemon requirement for signing [tor-browser-build]

### 16.0a7

- Date: 2026-06-04
- Version: 16.0a7
- Original notes: https://github.com/mullvad/mullvad-browser/releases/tag/16.0a7
- Permalink: https://whatsnew.fyi/product/mullvad-browser/releases/16.0a7
- Labels: Pre-release; Platforms: Desktop

- **changed** — Updated Firefox to 151.0a1
- **changed** — Updated NoScript to 13.6.19.90401984
- **changed** — Updated uBlock Origin to 1.71.0
- **fixed** — Switch resource:// modules to use moz-src
- **changed** — Use settings config to hide settings, rather than data-hidden-from-search or commenting out
- **changed** — Hide the settings privacy card
- **fixed** — Fix date format leak in Firefox 151
- **fixed** — Privacy settings are broken in 151
- **changed** — Change how we hide SSO setting for windows
- **changed** — Update toolchains for Firefox 151
- **fixed** — Fix clean section in rbm.local.conf.example
- **changed** — Switch from ftp.gnu.org to ftpmirror.gnu.org
- **fixed** — Incorrectly generated Bugzilla query link in generate-bugzilla-triage-csv.py
- **fixed** — Define GetAddrInfoExCancel on mingw
- **fixed** — Stop copying permissions from .mar in dmg2mar

* All Platforms
   * Updated Firefox to 151.0a1
   * Updated NoScript to 13.6.19.90401984
   * Updated uBlock Origin to 1.71.0
   * Bug 43824: Switch resource:// modules to use moz-src: [tor-browser]
   * Bug 44630: Use settings config to hide settings, rather than data-hidden-from-search or commenting out [tor-browser]
   * Bug 44829: Hide the settings privacy card [tor-browser]
   * Bug 44869: Rebase alpha onto 151 [tor-browser]
   * Bug 44903: Use the `support-page` instead of `tor-manual-page` in `moz-support-link` [tor-browser]
   * Bug 44989: Backport Bug 2040704: Fix date format leak in Firefox 151 [tor-browser]
   * Bug 44990: CI failing due to dubious ownership of cached repo [tor-browser]
   * Bug 44999: Privacy settings are broken in 151 [tor-browser]
 * Windows
   * Bug 44745: Change how we hide SSO setting for windows [tor-browser]
##### Build System
   * All Platforms
     * Bug 41779: Update toolchains for Firefox 151 [tor-browser-build]
     * Bug 41781: Fix clean section in rbm.local.conf.example [tor-browser-build]
     * Bug 41792: Switch from ftp.gnu.org to ftpmirror.gnu.org [tor-browser-build]
     * Bug 41806: `make list_toolchain_updates` should check var/firefox_platform_version [tor-browser-build]
     * Bug 41807: Incorrectly generated Bugzilla query link in generate-bugzilla-triage-csv.py [tor-browser-build]
   * Windows
     * Bug 41810: Define GetAddrInfoExCancel on mingw [tor-browser-build]
   * macOS
     * Bug 41793: Stop copying permissions from .mar in dmg2mar [tor-browser-build]

### 15.0.14

- Date: 2026-05-19
- Version: 15.0.14
- Original notes: https://github.com/mullvad/mullvad-browser/releases/tag/15.0.14
- Permalink: https://whatsnew.fyi/product/mullvad-browser/releases/15.0.14
- Labels: Platforms: Desktop

- **changed** — Updated Firefox to 140.11.0esr
- **changed** — Updated NoScript to 13.6.19.1984
- **security** — Backported security fixes from Firefox 151

* All Platforms
   * Updated Firefox to 140.11.0esr
   * Updated NoScript to 13.6.19.1984
   * Bug 44958: Backport Security Fixes from Firefox 151 [tor-browser]
##### Build System
   * All Platforms
     * Bug 41781: Fix clean section in rbm.local.conf.example [tor-browser-build]

### 15.0.12

- Date: 2026-05-07
- Version: 15.0.12
- Original notes: https://github.com/mullvad/mullvad-browser/releases/tag/15.0.12
- Permalink: https://whatsnew.fyi/product/mullvad-browser/releases/15.0.12
- Labels: Platforms: Desktop

- **changed** — Updated Firefox to 140.10.2esr

* All Platforms
   * Updated Firefox to 140.10.2esr
##### Build System
   * All Platforms
     * Bug 41781: Fix clean section in rbm.local.conf.example [tor-browser-build]

### 16.0a6

- Date: 2026-05-05
- Version: 16.0a6
- Original notes: https://github.com/mullvad/mullvad-browser/releases/tag/16.0a6
- Permalink: https://whatsnew.fyi/product/mullvad-browser/releases/16.0a6
- Labels: Pre-release; Platforms: Desktop

- **changed** — Updated Firefox to 150.0a1
- **changed** — Updated NoScript to 13.6.17.90101984
- **changed** — Updated Mullvad Browser Extension to 0.9.10
- **changed** — Use border radius for letterboxing
- **changed** — Customize the flags for alternate Application Data directories
- **fixed** — Hide the Firefox mascot in about:neterror
- **fixed** — Error in privacy preference initialisation due to missing dataCollectionViewProfilesMultiProfileBackupWarning
- **fixed** — Fontvis is missing Segoe MDL2 Assets on Windows
- **changed** — Disable widget.wayland.fractional-scale.enabled on Linux
- **changed** — Start using LTO for firefox project
- **changed** — Update toolchains for Firefox 150

* All Platforms
   * Updated Firefox to 150.0a1
   * Updated NoScript to 13.6.17.90101984
   * Updated Mullvad Browser Extension to 0.9.10
   * Bug 528: Rebase Mullvad Browser alpha onto 150.0a1 [mullvad-browser]
   * Bug 44402: Re-enable ESLint rule mozilla/no-browser-refs-in-toolkit as an error
   * Bug 44560: Customize the flags for alternate 'Application Data' directories [tor-browser]
   * Bug 44685: Use border radius for letterboxing [tor-browser]
   * Bug 44749: Check search engines parameter replacements [tor-browser]
   * Bug 44828: Remove browser module references from toolkit/modules/ActorManagerParent.sys.mjs [tor-browser]
   * Bug 44832: Hide the Firefox mascot in about:neterror [tor-browser]
   * Bug 44847: Drop letterboxing sidebar rounded corner logic [tor-browser]
   * Bug 44865: Block chrome://*/locale/* to content [tor-browser]
   * Bug 44870: Remove legacy branch from gitlab templates [tor-browser]
   * Bug 44895: Undo the patch for #44772 [tor-browser]
   * Bug 44902: Error in privacy preference initialisation due to missing `dataCollectionViewProfilesMultiProfileBackupWarning` [tor-browser]
   * Bug 31860: Start using LTO for firefox project [tor-browser-build]
 * Windows
   * Bug 44862: Fontvis is missing Segoe MDL2 Assets [tor-browser]
   * Bug 44868: Backport 138c33ea964b2e0a4875aadc39d8a948e0c2aace to 150 to fix Windows builds [tor-browser]
 * Linux
   * Bug 44521: Disable widget.wayland.fractional-scale.enabled [tor-browser]
##### Build System
   * All Platforms
     * Bug 41764: Update toolchains for Firefox 150 [tor-browser-build]
     * Bug 41767: Add jwilde to allowed signer for browser projects [tor-browser-build]
     * Bug 41778: Remove base-browser from protected-branches.py [tor-browser-build]
     * Bug 41780: Create sha256sums-unsigned-build.txt in artifacts/$platform directories [tor-browser-build]
     * Bug 41786: Add comment to rbm.local.conf.example warning about potential recursive loops in tmp_dir definition [tor-browser-build]
     * Bug 40106: Improve error message in case of recursive definition [rbm]
   * Windows
     * Bug 44853: Update target in mozconfig-windows-x86_64 and mozconfig-windows-i686 [tor-browser]
   * macOS
     * Bug 41773: Change the position of -mindepth when creating the dmg [tor-browser-build]

### 15.0.11

- Date: 2026-04-28
- Version: 15.0.11
- Original notes: https://github.com/mullvad/mullvad-browser/releases/tag/15.0.11
- Permalink: https://whatsnew.fyi/product/mullvad-browser/releases/15.0.11
- Labels: Platforms: Desktop

- **changed** — Updated Firefox to 140.10.1esr
- **changed** — Updated NoScript to 13.6.18.1984

* All Platforms
   * Updated Firefox to 140.10.1esr
   * Updated NoScript to 13.6.18.1984
   * Bug 529: Rebase Mullvad Browser stable onto 140.10.1esr [mullvad-browser]