Enables ManifestV2 for extensions in Chrome 140+

patch-chrome-mv2-2025-11-18.ps1

<# 1. To patch dll in a protected folder like "c:\program files" run this script as Administrator.
   2. If your Windows isn't configured to run ps1 files, you can run it from command prompt like this:
      powershell -ep bypass -noprofile "patch-chrome-mv2.ps1"
#>
param([string]$dll, [string]$dir = $pwd)

function doPatch([string]$path, [string]$pathLabel = '') {
    $dll = $script:dll = if ($path.EndsWith('\')) { Join-Path $path chrome.dll } else { $path }
    if (!(Test-Path -literal $dll)) { return }
    $localAppData = [Environment]::GetFolderPath('LocalApplicationData')
    write-host -f yellow "`n$(@($pathLabel, (split-path $dll).Replace($localAppData, '%LocalAppData%')) -join ' ')"

    $script:stream = [IO.File]::Open($dll, [IO.FileMode]::Open, [IO.FileAccess]::Read, [IO.FileShare]::ReadWrite)
    $reader = [IO.BinaryReader]$stream
    $enc = [Text.Encoding]::GetEncoding(28591)
    $features = @(
        '-ExtensionManifestV2Unsupported'
        '-ExtensionManifestV2Disabled'
        '-ExtensionsManifestV3Only'
        '+AllowLegacyMV2Extensions'
    )

    write-host -f DarkGray "`tREADING Chrome.dll..."
    [void]$stream.seek(0x3C, 0)
    $coff = $reader.ReadUint32() + 4
    $coffSize = 20
    [void]$stream.seek($coff, 0)
    $bytes = $reader.ReadBytes($coffSize + 2)
    $is64 = [BitConverter]::ToUInt16($bytes, 0) -eq 0x8664
    $isPE32 = [BitConverter]::ToUInt16($bytes, $coffSize) -eq 0x010b
    [void]$stream.seek($coff + $coffSize + 24 + 4 * $isPE32, 0)
    $imageBase = if ($isPE32) { $reader.ReadUInt32() } else { $reader.ReadUInt64() }

    # find sections
    $extraHeaderSize = [BitConverter]::ToUInt16($bytes, 16)
    $numSections = [BitConverter]::ToUInt16($bytes, 2)
    [void]$stream.seek($coff + $coffSize + $extraHeaderSize, 0)
    $sections = @{}
    foreach ($i in 1..$numSections) {
        $sec = $reader.ReadBytes(40)
        $i = $sec.IndexOf([byte]0)
        $name = $enc.GetString($sec, 0, $(if ($i -lt 0) { 8 } else { [math]::min(8, $i) }))
        if ($name -eq '.rdata' -or $name -eq '.data') {
            $sections[$name.substring(1)] = @{
                addr = $imageBase + [uint64][BitConverter]::ToUInt32($sec, 12);
                size = [BitConverter]::ToUInt32($sec, 16);
                filePos = [BitConverter]::ToUInt32($sec, 20);
            }
            if ($sections.count -eq 2) { break }
        }
    }

    # .rdata section
    if (!$sections.rdata) {
        return "Could not find .rdata section"
    }
    [void]$stream.seek($sections.rdata.filePos, 0)
    $cur = 0
    $step = 1MB
    $featArea = 1kB
    $featData = [ordered]@{}
    while ($cur -lt $sections.rdata.size) {
        $bytes = $reader.ReadBytes($step)
        $str = $enc.GetString($bytes)
        foreach ($feat in $features) {
            if ($featData[$feat]) { continue }
            $pos = $str.indexOf($feat.substring(1))
            if ($pos -lt 0) { break }
            $featData[$feat] = $sections.rdata.addr + $cur + $pos
        }
        if ($featData.count -eq $features.length) { break }
        $cur += $step - $featArea
        [void]$stream.seek(-$featArea, [IO.SeekOrigin]::Current)
    }
    if (!$sections.data) {
        return "Could not find .data section"
    }

    # .data section
    [void]$stream.seek($sections.data.filePos, 0)
    $len = $sections.data.size
    $bytes = $reader.ReadBytes($len)
    if ($is64) { $words = [uint64[]]::new($len -shr 3) }
        else { $words = [uint32[]]::new($len -shr 2) }
    [Buffer]::BlockCopy($bytes, 0, $words, 0, $len)
    $bytes = $null
    $copied = $false
    $wordType = $words[0].getType()
    foreach ($feat in $featData.Keys) {
        $needle = $featData[$feat]
        $needle = $needle -as $wordType
        $val = ($feat[0] -eq '+') -as $wordType
        $feat = $feat.substring(1)
        $i = $words.indexOf($needle)
        while ($i -ge 0 -and !($words[$i + 1] -in 0,1)) {
            $i = [Array]::IndexOf($words, $needle, $i + 1)
        }
        if (!++$i) {
            return "Could not find $feat pointer in .data section"
        }
        if ($words[$i] -eq $val) {
            write-host -f darkcyan "`tAlready patched $feat"
            continue
        }
        if (!$copied) {
            $copied = $true
            $stream.close()
            $script:stream = [IO.File]::Open($dll, [IO.FileMode]::Open, [IO.FileAccess]::ReadWrite, [IO.FileShare]::Read)
            if (test-path -literal "$dll.BAK") {
                write-host -f darkgray "`tFound an existing backup of the original dll."
            } else {
                write-host -f darkgray "`tBacking up the original dll..."
                [IO.File]::Copy($dll, "$dll.BAK")
            }
        }
        write-host -f cyan "`tPatching $feat..."
        [void]$stream.seek($sections.data.filePos + $i * (4 + 4 * $is64), 0)
        $stream.WriteByte($val)
    }
    write-host -f green "`tDONE."
}

function tryPatch($a, $b) {
    try {
        $err = doPatch $a $b
    } catch {
        $a = ([regex]'\): "(.+)"').match($Error[0]).Groups[1].Value
        if ($a) { $err = $a.Replace($dll, 'chrome.dll') } else { $Error[0] }
    }
    if ($stream) {
        $stream.close()
        $script:stream = $null
    }
    if ($err) {
        write-host -f red "`t$err"
        $script:err = $true
    }
    [GC]::Collect()
}

$err = $false
if ($dll) {
    tryPatch $dll
} else {
    $pathsDone = @{}
    tryPatch ((gi -literal $dir).fullName + '\') 'CURRENT DIRECTORY'
    ('HKLM', 'HKCU') | %{
        $hive = $_
        ('', '\Wow6432Node') | %{
            $key = "${hive}:\SOFTWARE$_\Google\Update\Clients"
            gci -ea silentlycontinue $key -r | gp | ?{ $_.CommandLine } | %{
                $path = $_.CommandLine -replace '"(.+?\\\d+\.\d+\.\d+\.\d+\\).+', '$1'
                if (!$pathsDone[$path.toLower()]) {
                    tryPatch $path REGISTRY
                    $pathsDone[$path.toLower()] = $true
                }
            }
        }
    }
}

if ($err) { read-host "Press Enter key to exit" }

i wonder if this same script would work on edge if i change the "chrome.dll" lines to "msedge.dll" :/

It's probably not that simple; it's already crashing on the Chromium DLL (changes are supposedly made to the file, but they're ignored as if they were just irrelevant noise), so the others would need fixes specific to non-branded versions and Edge (though my Edge doesn't seem to be picky and doesn't need that).

It still works today. Thank you a lot OP! ^_^