diff --git a/app/Services/ProxyPortParser.php b/app/Services/ProxyPortParser.php
index 3cad67ce6e..5d118ed278 100644
--- a/app/Services/ProxyPortParser.php
+++ b/app/Services/ProxyPortParser.php
@@ -7,11 +7,30 @@ use Symfony\Component\Yaml\Yaml;
 
 class ProxyPortParser
 {
+    /**
+     * Matches a Docker Compose variable: $VAR, ${VAR}, or ${VAR} with a :-, -, :?, ?, :+, or + modifier.
+     */
+    private const VARIABLE_PATTERN = '/\$(?:\{[A-Za-z_][A-Za-z0-9_]*(?::?[-?+][^${}]*)?\}|[A-Za-z_][A-Za-z0-9_]*)/';
+
+    /**
+     * Matches ${VAR:-default} and ${VAR-default}; group 1 is the default.
+     */
+    private const DEFAULT_PATTERN = '/\$\{[A-Za-z_][A-Za-z0-9_]*:?-([^${}]*)\}/';
+
+    /**
+     * Characters a port entry may contain outside of its variables.
+     */
+    private const SAFE_REMAINDER_PATTERN = '/^[0-9A-Za-z.:\[\]\/-]*$/D';
+
     /**
      * Validates the proxy ports like Docker Compose does and returns the fixed host ports.
      * Ports that Docker publishes to a random host port or to a port range are validated
      * but not returned: the caller checks each returned port over its own SSH connection.
      *
+     * Docker Compose interpolates variables when it starts the proxy, so a variable never makes
+     * a port invalid: a variable with a default is checked as its default, and a port that still
+     * depends on a variable (or whose default is not a valid port) is accepted but not returned.
+     *
      * @return list<int>
      */
     public static function fromConfiguration(string $configuration): array
@@ -53,20 +72,27 @@ class ProxyPortParser
 
     private static function publishedPort(mixed $configuredPort): ?int
     {
+        if (is_string($configuredPort) && self::containsVariable($configuredPort)) {
+            return self::publishedPortWithVariables($configuredPort);
+        }
+
         if (is_array($configuredPort)) {
             if (array_is_list($configuredPort) || ! array_key_exists('target', $configuredPort)) {
                 self::invalid();
             }
 
+            $configuredPort = self::resolveLongSyntaxVariables($configuredPort, $hasUnresolvedVariables);
+
             self::validateProtocol($configuredPort['protocol'] ?? null);
             if (array_key_exists('host_ip', $configuredPort)) {
                 self::validateHostIp($configuredPort['host_ip']);
             }
             $target = self::portNumber($configuredPort['target']);
-
-            return array_key_exists('published', $configuredPort)
+            $publishedPort = array_key_exists('published', $configuredPort)
                 ? self::portOrRange($configuredPort['published'])
                 : $target;
+
+            return $hasUnresolvedVariables ? null : $publishedPort;
         }
 
         if (! is_int($configuredPort) && ! is_string($configuredPort)) {
@@ -108,6 +134,87 @@ class ProxyPortParser
             : self::hostPort($parts[0], $parts[1]);
     }
 
+    private static function containsVariable(string $value): bool
+    {
+        return preg_match(self::VARIABLE_PATTERN, $value) === 1;
+    }
+
+    /**
+     * Rejects an entry with anything but variables and port syntax, then replaces each
+     * variable that has a default with the default. Returns null if a variable remains.
+     */
+    private static function resolveDefaults(string $value): ?string
+    {
+        if (preg_match(self::SAFE_REMAINDER_PATTERN, preg_replace(self::VARIABLE_PATTERN, '', $value)) !== 1) {
+            self::invalid();
+        }
+
+        $resolved = preg_replace_callback(self::DEFAULT_PATTERN, fn (array $matches): string => $matches[1], $value);
+
+        return self::containsVariable($resolved) ? null : $resolved;
+    }
+
+    private static function publishedPortWithVariables(string $configuredPort): ?int
+    {
+        $resolved = self::resolveDefaults($configuredPort);
+        if ($resolved === null) {
+            return null;
+        }
+
+        try {
+            return self::publishedPort($resolved);
+        } catch (\InvalidArgumentException) {
+            // The variable may be set to a valid value when Docker Compose starts the proxy.
+            return null;
+        }
+    }
+
+    /**
+     * Replaces long-syntax fields that use variables with their defaults. A field without a usable
+     * default is replaced with a valid placeholder (or removed) so the other fields are still validated.
+     *
+     * @param  array<string, mixed>  $configuredPort
+     * @return array<string, mixed>
+     */
+    private static function resolveLongSyntaxVariables(array $configuredPort, ?bool &$hasUnresolvedVariables): array
+    {
+        $hasUnresolvedVariables = false;
+        $validators = [
+            'target' => fn (string $value) => self::portOrRange($value),
+            'published' => fn (string $value) => self::portOrRange($value),
+            'host_ip' => fn (string $value) => self::validateHostIp($value),
+            'protocol' => fn (string $value) => self::validateProtocol($value),
+        ];
+
+        foreach ($validators as $field => $validate) {
+            $value = $configuredPort[$field] ?? null;
+            if (! is_string($value) || ! self::containsVariable($value)) {
+                continue;
+            }
+
+            $resolved = self::resolveDefaults($value);
+            if ($resolved !== null) {
+                try {
+                    $validate($resolved);
+                    $configuredPort[$field] = $resolved;
+
+                    continue;
+                } catch (\InvalidArgumentException) {
+                    // The variable may be set to a valid value when Docker Compose starts the proxy.
+                }
+            }
+
+            $hasUnresolvedVariables = true;
+            if (in_array($field, ['target', 'published'], true)) {
+                $configuredPort[$field] = 1;
+            } else {
+                unset($configuredPort[$field]);
+            }
+        }
+
+        return $configuredPort;
+    }
+
     /**
      * Returns the fixed host port, or null for a random host port or a port range.
      */
diff --git a/tests/Feature/Proxy/ProxyPortVariablesTest.php b/tests/Feature/Proxy/ProxyPortVariablesTest.php
new file mode 100644
index 0000000000..193de09421
--- /dev/null
+++ b/tests/Feature/Proxy/ProxyPortVariablesTest.php
@@ -0,0 +1,111 @@
+<?php
+
+use App\Actions\Proxy\CheckProxy;
+use App\Actions\Proxy\GetProxyConfiguration;
+use App\Actions\Proxy\SaveProxyConfiguration;
+use App\Actions\Proxy\StartProxy;
+use App\Actions\Server\ConfigureTrafficAnalytics;
+use App\Actions\Server\StartSentinel;
+use App\Enums\ProxyTypes;
+use App\Events\ProxyStatusChanged;
+use App\Events\ProxyStatusChangedUI;
+use App\Jobs\RestartProxyJob;
+use App\Models\InstanceSettings;
+use App\Models\PrivateKey;
+use App\Models\Server;
+use App\Models\Team;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Facades\Event;
+use Illuminate\Support\Facades\Process;
+use Illuminate\Support\Facades\Queue;
+
+uses(RefreshDatabase::class);
+
+/**
+ * Docker Compose interpolates variables in proxy ports, so Coolify must never refuse to save,
+ * start, or restart a proxy because a port uses a variable (like v4.3.23 did not).
+ */
+beforeEach(function () {
+    Server::flushIdentityMap();
+    Event::fake([ProxyStatusChanged::class, ProxyStatusChangedUI::class]);
+    InstanceSettings::forceCreate(['id' => 0]);
+    config(['constants.ssh.mux_enabled' => false]);
+    Process::fake();
+
+    $team = Team::factory()->create();
+    $this->server = Server::factory()->create([
+        'team_id' => $team->id,
+        'user' => 'cooluser',
+        'private_key_id' => PrivateKey::factory()->create(['team_id' => $team->id])->id,
+    ]);
+    $this->server->settings->update(['is_reachable' => true, 'is_usable' => true, 'force_disabled' => false]);
+    $this->server->proxy->type = ProxyTypes::TRAEFIK->value;
+    $this->server->proxy->status = 'exited';
+    $this->server->save();
+    $this->server->refresh();
+});
+
+dataset('proxy port variables', [
+    'host port default' => ['${HTTP_PORT:-80}:80'],
+    'host port without default' => ['${HTTP_PORT}:80'],
+    'host IP with a host port default' => ['127.0.0.1:${P:-8080}:8080'],
+    'host IP default' => ['${BIND_IP:-0.0.0.0}:80:80'],
+]);
+
+function proxyConfigurationWithPort(string $port): string
+{
+    return "services:\n  traefik:\n    image: traefik:v3.6\n    ports:\n      - '{$port}'\n      - '443:443'\n";
+}
+
+it('saves a proxy configuration whose ports use variables', function (string $port) {
+    $configuration = proxyConfigurationWithPort($port);
+
+    SaveProxyConfiguration::run($this->server, $configuration);
+
+    expect($this->server->fresh()->proxy->last_saved_proxy_configuration)->toBe($configuration);
+})->with('proxy port variables');
+
+it('starts a proxy whose ports use variables', function (string $port) {
+    $this->server->proxy->last_saved_proxy_configuration = proxyConfigurationWithPort($port);
+    $this->server->save();
+
+    StartProxy::run($this->server, async: false, force: true);
+
+    Process::assertRan(fn ($process) => str_contains($process->command, 'docker compose -f /data/coolify/proxy/docker-compose.yml up -d --wait --remove-orphans'));
+})->with('proxy port variables');
+
+it('restarts a proxy whose ports use variables', function (string $port) {
+    Queue::fake();
+    $this->server->proxy->last_saved_proxy_configuration = proxyConfigurationWithPort($port);
+    $this->server->save();
+
+    $job = new RestartProxyJob($this->server);
+    $job->handle();
+
+    expect($job->activity_id)->not->toBeNull()
+        ->and($this->server->fresh()->proxy->status)->toBe('restarting');
+})->with('proxy port variables');
+
+it('asks to start a stopped proxy whose ports use variables and checks only concrete ports', function () {
+    $this->server->proxy->last_saved_proxy_configuration = "services:\n  traefik:\n    image: traefik:v3.6\n    ports:\n      - '\${HTTP_PORT:-8081}:80'\n      - '\${HTTPS_PORT}:443'\n";
+    $this->server->save();
+
+    expect(CheckProxy::run($this->server))->toBeTrue();
+
+    Process::assertRan(fn ($process) => str_contains($process->command, "sport = ':8081'"));
+    Process::assertDidntRun(fn ($process) => str_contains($process->command, 'sport = ') && str_contains($process->command, '${'));
+});
+
+it('configures traffic analytics for a proxy whose ports use variables', function () {
+    Queue::fake();
+    StartSentinel::partialMock()->shouldReceive('handle')->atLeast()->once();
+    GetProxyConfiguration::partialMock()->shouldReceive('handle')->once()->andReturn(proxyConfigurationWithPort('${HTTP_PORT}:80'));
+    SaveProxyConfiguration::partialMock()->shouldReceive('handle')->once();
+    $this->server->proxy->status = 'running';
+    $this->server->save();
+
+    ConfigureTrafficAnalytics::run($this->server, true);
+
+    expect($this->server->fresh()->isTrafficAnalyticsEnabled())->toBeTrue();
+    Queue::assertPushed(RestartProxyJob::class);
+});
diff --git a/tests/Unit/ProxyPortValidationTest.php b/tests/Unit/ProxyPortValidationTest.php
index 1275f181ab..2e8b13a4a9 100644
--- a/tests/Unit/ProxyPortValidationTest.php
+++ b/tests/Unit/ProxyPortValidationTest.php
@@ -17,6 +17,32 @@ it('extracts normalized published proxy ports from valid compose syntax', functi
     'long syntax with a published range' => ["services:\n  caddy:\n    ports:\n      - target: 443\n        published: '8443-8444'\n        protocol: UDP\n", []],
 ]);
 
+it('accepts Docker Compose variables and checks only ports with a resolvable default', function (mixed $ports, array $expected) {
+    $configuration = Yaml::dump(['services' => ['traefik' => ['ports' => $ports]]], 8, 2);
+
+    expect(ProxyPortParser::fromConfiguration($configuration))->toBe($expected);
+})->with([
+    'host port default' => [['${HTTP_PORT:-80}:80'], [80]],
+    'host port default without colon' => [['${HTTP_PORT-80}:80'], [80]],
+    'host port without default' => [['${HTTP_PORT}:80'], []],
+    'unbraced host port' => [['$HTTP_PORT:80'], []],
+    'required host port' => [['${HTTP_PORT:?HTTP_PORT must be set}:80'], []],
+    'alternative host port' => [['${HTTP_PORT:+8080}:80'], []],
+    'host IP with a host port default' => [['127.0.0.1:${P:-8080}:8080'], [8080]],
+    'host IP default' => [['${BIND_IP:-0.0.0.0}:80:80'], [80]],
+    'host IP without default' => [['${BIND_IP}:443:443'], []],
+    'container port variable' => [['8080:${CONTAINER_PORT}'], []],
+    'default with protocol' => [['${HTTPS_PORT:-443}:443/udp'], [443]],
+    'protocol variable' => [['443:443/${PROTOCOL:-udp}'], [443]],
+    'invalid default is skipped like an unset variable' => [['${HTTP_PORT:-abc}:80'], []],
+    'default range' => [['${RANGE:-10000-10100}:10000-10100'], []],
+    'mixed with literal ports' => [['${HTTP_PORT:-80}:80', '${HTTPS_PORT}:443', '8080:8080'], [80, 8080]],
+    'long syntax published default' => [[['target' => 80, 'published' => '${HTTP_PORT:-8080}']], [8080]],
+    'long syntax published variable' => [[['target' => 80, 'published' => '${HTTP_PORT}']], []],
+    'long syntax host IP default' => [[['target' => 80, 'published' => 80, 'host_ip' => '${BIND_IP:-127.0.0.1}']], [80]],
+    'long syntax target variable' => [[['target' => '${TARGET}', 'published' => 9000]], []],
+]);
+
 it('rejects malformed proxy port values', function (mixed $port) {
     $configuration = Yaml::dump(['services' => ['traefik' => ['ports' => [$port]]]], 8, 2);
 
@@ -30,7 +56,11 @@ it('rejects malformed proxy port values', function (mixed $port) {
     'decimal' => 80.5,
     'scientific notation' => '8e1',
     'comma separated' => '80,443',
-    'environment variable' => '${HTTP_PORT:-80}:80',
+    'environment variable followed by a semicolon' => '${HTTP_PORT:-80};id:80',
+    'environment variable with command substitution' => '${HTTP_PORT}$(id):80',
+    'environment variable with backticks' => '`id`${HTTP_PORT}:80',
+    'environment variable default with command substitution' => '${HTTP_PORT:-$(id)}:80',
+    'environment variable with a pipe' => '${HTTP_PORT}:80|id',
     'leading whitespace' => ' 80',
     'trailing whitespace' => '80 ',
     'newline' => "80\nid",
@@ -68,6 +98,8 @@ it('rejects malformed proxy ports in long compose syntax', function (array $port
     'invalid protocol' => [['target' => 80, 'published' => 8080, 'protocol' => 'http']],
     'reversed published range' => [['target' => 80, 'published' => '90-80']],
     'host injection' => [['target' => 80, 'published' => 8080, 'host_ip' => '$(id)']],
+    'variable with command substitution' => [['target' => 80, 'published' => '${HTTP_PORT}$(id)']],
+    'variable with an invalid protocol' => [['target' => 80, 'published' => '${HTTP_PORT}', 'protocol' => 'http']],
 ]);
 
 it('rejects invalid proxy port collection shapes', function (mixed $ports) {