diff --git a/app/Jobs/ApplicationDeploymentJob.php b/app/Jobs/ApplicationDeploymentJob.php
index c9f0f1eef..91c81b6ff 100644
--- a/app/Jobs/ApplicationDeploymentJob.php
+++ b/app/Jobs/ApplicationDeploymentJob.php
@@ -2196,7 +2196,7 @@ private function clone_repository()
         $this->create_workdir();
         $this->execute_remote_command(
             [
-                executeInDocker($this->deployment_uuid, "cd {$this->workdir} && git log -1 {$this->commit} --pretty=%B"),
+                executeInDocker($this->deployment_uuid, "cd {$this->workdir} && git log -1 ".escapeshellarg($this->commit)." --pretty=%B"),
                 'hidden' => true,
                 'save' => 'commit_message',
             ]
diff --git a/app/Livewire/Project/Application/General.php b/app/Livewire/Project/Application/General.php
index 008bd3905..fccd17217 100644
--- a/app/Livewire/Project/Application/General.php
+++ b/app/Livewire/Project/Application/General.php
@@ -37,7 +37,7 @@ class General extends Component
     #[Validate(['required'])]
     public string $gitBranch;
 
-    #[Validate(['string', 'nullable'])]
+    #[Validate(['string', 'nullable', 'regex:/^[a-zA-Z0-9][a-zA-Z0-9._\-\/]*$/'])]
     public ?string $gitCommitSha = null;
 
     #[Validate(['string', 'nullable'])]
@@ -184,7 +184,7 @@ protected function rules(): array
             'fqdn' => 'nullable',
             'gitRepository' => 'required',
             'gitBranch' => 'required',
-            'gitCommitSha' => 'nullable',
+            'gitCommitSha' => ['nullable', 'regex:/^[a-zA-Z0-9][a-zA-Z0-9._\-\/]*$/'],
             'installCommand' => 'nullable',
             'buildCommand' => 'nullable',
             'startCommand' => 'nullable',
diff --git a/app/Livewire/Project/Application/Rollback.php b/app/Livewire/Project/Application/Rollback.php
index e8edf72fa..3edd77833 100644
--- a/app/Livewire/Project/Application/Rollback.php
+++ b/app/Livewire/Project/Application/Rollback.php
@@ -50,6 +50,8 @@ public function rollbackImage($commit)
     {
         $this->authorize('deploy', $this->application);
 
+        $commit = validateGitRef($commit, 'rollback commit');
+
         $deployment_uuid = new Cuid2;
 
         $result = queue_application_deployment(
diff --git a/app/Livewire/Project/Application/Source.php b/app/Livewire/Project/Application/Source.php
index ab2517f2b..422dd6b28 100644
--- a/app/Livewire/Project/Application/Source.php
+++ b/app/Livewire/Project/Application/Source.php
@@ -30,7 +30,7 @@ class Source extends Component
     #[Validate(['required', 'string'])]
     public string $gitBranch;
 
-    #[Validate(['nullable', 'string'])]
+    #[Validate(['nullable', 'string', 'regex:/^[a-zA-Z0-9][a-zA-Z0-9._\-\/]*$/'])]
     public ?string $gitCommitSha = null;
 
     #[Locked]
diff --git a/app/Models/Application.php b/app/Models/Application.php
index a4f51780e..34ab4141e 100644
--- a/app/Models/Application.php
+++ b/app/Models/Application.php
@@ -1686,7 +1686,8 @@ public function fqdns(): Attribute
 
     protected function buildGitCheckoutCommand($target): string
     {
-        $command = "git checkout $target";
+        $escapedTarget = escapeshellarg($target);
+        $command = "git checkout {$escapedTarget}";
 
         if ($this->settings->is_git_submodules_enabled) {
             $command .= ' && git submodule update --init --recursive';
diff --git a/bootstrap/helpers/api.php b/bootstrap/helpers/api.php
index edb1e59a1..1b03a4d37 100644
--- a/bootstrap/helpers/api.php
+++ b/bootstrap/helpers/api.php
@@ -92,7 +92,7 @@ function sharedDataApplications()
         'static_image' => Rule::enum(StaticImageTypes::class),
         'domains' => 'string|nullable',
         'redirect' => Rule::enum(RedirectTypes::class),
-        'git_commit_sha' => 'string',
+        'git_commit_sha' => ['string', 'regex:/^[a-zA-Z0-9][a-zA-Z0-9._\-\/]*$/'],
         'docker_registry_image_name' => 'string|nullable',
         'docker_registry_image_tag' => 'string|nullable',
         'install_command' => 'string|nullable',
diff --git a/bootstrap/helpers/shared.php b/bootstrap/helpers/shared.php
index 3e993dbf3..ce40466b2 100644
--- a/bootstrap/helpers/shared.php
+++ b/bootstrap/helpers/shared.php
@@ -147,6 +147,39 @@ function validateShellSafePath(string $input, string $context = 'path'): string
     return $input;
 }
 
+/**
+ * Validate that a string is a safe git ref (commit SHA, branch name, tag, or HEAD).
+ *
+ * Prevents command injection by enforcing an allowlist of characters valid for git refs.
+ * Valid: hex SHAs, HEAD, branch/tag names (alphanumeric, dots, hyphens, underscores, slashes).
+ *
+ * @param  string  $input  The git ref to validate
+ * @param  string  $context  Descriptive name for error messages
+ * @return string The validated input (trimmed)
+ *
+ * @throws \Exception If the input contains disallowed characters
+ */
+function validateGitRef(string $input, string $context = 'git ref'): string
+{
+    $input = trim($input);
+
+    if ($input === '' || $input === 'HEAD') {
+        return $input;
+    }
+
+    // Must not start with a hyphen (git flag injection)
+    if (str_starts_with($input, '-')) {
+        throw new \Exception("Invalid {$context}: must not start with a hyphen.");
+    }
+
+    // Allow only alphanumeric characters, dots, hyphens, underscores, and slashes
+    if (! preg_match('/^[a-zA-Z0-9][a-zA-Z0-9._\-\/]*$/', $input)) {
+        throw new \Exception("Invalid {$context}: contains disallowed characters. Only alphanumeric characters, dots, hyphens, underscores, and slashes are allowed.");
+    }
+
+    return $input;
+}
+
 function generate_readme_file(string $name, string $updated_at): string
 {
     $name = sanitize_string($name);
diff --git a/tests/Unit/GitRefValidationTest.php b/tests/Unit/GitRefValidationTest.php
new file mode 100644
index 000000000..58d07f4b7
--- /dev/null
+++ b/tests/Unit/GitRefValidationTest.php
@@ -0,0 +1,123 @@
+<?php
+
+/**
+ * Security tests for git ref validation (GHSA-mw5w-2vvh-mgf4).
+ *
+ * Ensures that git_commit_sha and related inputs are validated
+ * to prevent OS command injection via shell metacharacters.
+ */
+
+describe('validateGitRef', function () {
+    test('accepts valid hex commit SHAs', function () {
+        expect(validateGitRef('abc123def456'))->toBe('abc123def456');
+        expect(validateGitRef('a3e59e5c9'))->toBe('a3e59e5c9');
+        expect(validateGitRef('abc123def456abc123def456abc123def456abc123'))->toBe('abc123def456abc123def456abc123def456abc123');
+    });
+
+    test('accepts HEAD', function () {
+        expect(validateGitRef('HEAD'))->toBe('HEAD');
+    });
+
+    test('accepts empty string', function () {
+        expect(validateGitRef(''))->toBe('');
+    });
+
+    test('accepts branch and tag names', function () {
+        expect(validateGitRef('main'))->toBe('main');
+        expect(validateGitRef('feature/my-branch'))->toBe('feature/my-branch');
+        expect(validateGitRef('v1.2.3'))->toBe('v1.2.3');
+        expect(validateGitRef('release-2.0'))->toBe('release-2.0');
+        expect(validateGitRef('my_branch'))->toBe('my_branch');
+    });
+
+    test('trims whitespace', function () {
+        expect(validateGitRef('  abc123  '))->toBe('abc123');
+    });
+
+    test('rejects single quote injection', function () {
+        expect(fn () => validateGitRef("HEAD'; id >/tmp/poc; #"))
+            ->toThrow(Exception::class);
+    });
+
+    test('rejects semicolon command separator', function () {
+        expect(fn () => validateGitRef('abc123; rm -rf /'))
+            ->toThrow(Exception::class);
+    });
+
+    test('rejects command substitution with $()', function () {
+        expect(fn () => validateGitRef('$(whoami)'))
+            ->toThrow(Exception::class);
+    });
+
+    test('rejects backtick command substitution', function () {
+        expect(fn () => validateGitRef('`whoami`'))
+            ->toThrow(Exception::class);
+    });
+
+    test('rejects pipe operator', function () {
+        expect(fn () => validateGitRef('abc | cat /etc/passwd'))
+            ->toThrow(Exception::class);
+    });
+
+    test('rejects ampersand operator', function () {
+        expect(fn () => validateGitRef('abc & whoami'))
+            ->toThrow(Exception::class);
+    });
+
+    test('rejects hash comment injection', function () {
+        expect(fn () => validateGitRef('abc #'))
+            ->toThrow(Exception::class);
+    });
+
+    test('rejects newline injection', function () {
+        expect(fn () => validateGitRef("abc\nwhoami"))
+            ->toThrow(Exception::class);
+    });
+
+    test('rejects redirect operators', function () {
+        expect(fn () => validateGitRef('abc > /tmp/out'))
+            ->toThrow(Exception::class);
+    });
+
+    test('rejects hyphen-prefixed input (git flag injection)', function () {
+        expect(fn () => validateGitRef('--upload-pack=malicious'))
+            ->toThrow(Exception::class);
+    });
+
+    test('rejects the exact PoC payload from advisory', function () {
+        expect(fn () => validateGitRef("HEAD'; whoami >/tmp/coolify_poc_git; #"))
+            ->toThrow(Exception::class);
+    });
+});
+
+describe('executeInDocker git log escaping', function () {
+    test('git log command escapes commit SHA to prevent injection', function () {
+        $maliciousCommit = "HEAD'; id; #";
+        $command = "cd /workdir && git log -1 ".escapeshellarg($maliciousCommit).' --pretty=%B';
+        $result = executeInDocker('test-container', $command);
+
+        // The malicious payload must not be able to break out of quoting
+        expect($result)->not->toContain("id;");
+        expect($result)->toContain("'HEAD'\\''");
+    });
+});
+
+describe('buildGitCheckoutCommand escaping', function () {
+    test('checkout command escapes target to prevent injection', function () {
+        $app = new \App\Models\Application;
+        $app->forceFill(['uuid' => 'test-uuid']);
+
+        $settings = new \App\Models\ApplicationSetting;
+        $settings->is_git_submodules_enabled = false;
+        $app->setRelation('settings', $settings);
+
+        $method = new \ReflectionMethod($app, 'buildGitCheckoutCommand');
+
+        $result = $method->invoke($app, 'abc123');
+        expect($result)->toContain("git checkout 'abc123'");
+
+        $result = $method->invoke($app, "abc'; id; #");
+        expect($result)->not->toContain("id;");
+        expect($result)->toContain("git checkout 'abc'");
+    });
+});