diff --git a/packages/aws-cdk-lib/aws-ec2/lib/cfn-init.ts b/packages/aws-cdk-lib/aws-ec2/lib/cfn-init.ts
index 5abcbc35fb926..2cd6fd24f0c8b 100644
--- a/packages/aws-cdk-lib/aws-ec2/lib/cfn-init.ts
+++ b/packages/aws-cdk-lib/aws-ec2/lib/cfn-init.ts
@@ -303,6 +303,10 @@ function deepMerge(target?: Record<string, any>, src?: Record<string, any>) {
   if (src == null) { return target; }
 
   for (const [key, value] of Object.entries(src)) {
+    if (key === '__proto__' || key === 'constructor') {
+      continue;
+    }
+
     if (Array.isArray(value)) {
       if (target[key] && !Array.isArray(target[key])) {
         throw new Error(`Trying to merge array [${value}] into a non-array '${target[key]}'`);
diff --git a/packages/aws-cdk-lib/aws-ec2/test/cfn-init.test.ts b/packages/aws-cdk-lib/aws-ec2/test/cfn-init.test.ts
index a5658931a2eb5..bf6823a598988 100644
--- a/packages/aws-cdk-lib/aws-ec2/test/cfn-init.test.ts
+++ b/packages/aws-cdk-lib/aws-ec2/test/cfn-init.test.ts
@@ -660,7 +660,7 @@ function dontExpectLine(lines: string[], re: RegExp) {
 }
 
 function cmdArg(command: string, argument: string) {
-  return new RegExp(`${escapeRegex(command)}(\.exe)? .*${escapeRegex(argument)}`);
+  return new RegExp(`${escapeRegex(command)}(\\.exe)? .*${escapeRegex(argument)}`);
 }
 
 function escapeRegex(s: string) {
diff --git a/packages/aws-cdk-lib/aws-ecs/lib/images/repository.ts b/packages/aws-cdk-lib/aws-ecs/lib/images/repository.ts
index 2a371804177b6..c73658177c4fa 100644
--- a/packages/aws-cdk-lib/aws-ecs/lib/images/repository.ts
+++ b/packages/aws-cdk-lib/aws-ecs/lib/images/repository.ts
@@ -8,7 +8,7 @@ import { ContainerImage, ContainerImageConfig } from '../container-image';
  * Regex pattern to check if it is an ECR image URL.
  *
  */
-const ECR_IMAGE_REGEX = /(^[a-zA-Z0-9][a-zA-Z0-9-_]*).dkr.ecr.([a-zA-Z0-9][a-zA-Z0-9-_]*).amazonaws.com(.cn)?\/.*/;
+const ECR_IMAGE_REGEX = /(^[a-zA-Z0-9][a-zA-Z0-9-_]*)\.dkr\.ecr\.([a-zA-Z0-9][a-zA-Z0-9-_]*)\.amazonaws.com(\.cn)?\/.*/;
 
 /**
  * The properties for an image hosted in a public or private repository.
diff --git a/packages/aws-cdk-lib/aws-eks/lib/kubectl-handler/helm/__init__.py b/packages/aws-cdk-lib/aws-eks/lib/kubectl-handler/helm/__init__.py
index ce5fe63925637..3a5656f46db91 100644
--- a/packages/aws-cdk-lib/aws-eks/lib/kubectl-handler/helm/__init__.py
+++ b/packages/aws-cdk-lib/aws-eks/lib/kubectl-handler/helm/__init__.py
@@ -100,8 +100,8 @@ def helm_handler(event, context):
 
 def get_oci_cmd(repository, version):
     # Generates OCI command based on pattern. Public ECR vs Private ECR are treated differently.
-    private_ecr_pattern = 'oci://(?P<registry>\d+.dkr.ecr.(?P<region>[a-z0-9\-]+).amazonaws.com)*'
-    public_ecr_pattern = 'oci://(?P<registry>public.ecr.aws)*'
+    private_ecr_pattern = 'oci://(?P<registry>\d+\.dkr\.ecr\.(?P<region>[a-z0-9\-]+)\.amazonaws\.com)*'
+    public_ecr_pattern = 'oci://(?P<registry>public\.ecr\.aws)*'
 
     private_registry = re.match(private_ecr_pattern, repository).groupdict()
     public_registry = re.match(public_ecr_pattern, repository).groupdict()
@@ -115,7 +115,7 @@ def get_oci_cmd(repository, version):
     elif public_registry['registry'] is not None:
         logger.info("Found AWS public repository, will use default region as deployment")
         region = os.environ.get('AWS_REGION', 'us-east-1')
-        
+
         if is_ecr_public_available(region):
             cmnd = [
                 f"aws ecr-public get-login-password --region us-east-1 | " \
@@ -124,7 +124,7 @@ def get_oci_cmd(repository, version):
         else:
             # `aws ecr-public get-login-password` and `helm registry login` not required as ecr public is not available in current region
             # see https://helm.sh/docs/helm/helm_registry_login/
-            cmnd = [f"helm pull {repository} --version {version} --untar"]   
+            cmnd = [f"helm pull {repository} --version {version} --untar"]
     else:
         logger.error("OCI repository format not recognized, falling back to helm pull")
         cmnd = [f"helm pull {repository} --version {version} --untar"]
@@ -144,7 +144,7 @@ def get_chart_from_oci(tmpdir, repository = None, version = None):
             output = subprocess.check_output(cmnd, stderr=subprocess.STDOUT, cwd=tmpdir, shell=True)
             logger.info(output)
 
-            # effectively returns "$tmpDir/$lastPartOfOCIUrl", because this is how helm pull saves OCI artifact. 
+            # effectively returns "$tmpDir/$lastPartOfOCIUrl", because this is how helm pull saves OCI artifact.
             # Eg. if we have oci://9999999999.dkr.ecr.us-east-1.amazonaws.com/foo/bar/pet-service repository, helm saves artifact under $tmpDir/pet-service
             return os.path.join(tmpdir, repository.rpartition('/')[-1])
         except subprocess.CalledProcessError as exc:
diff --git a/packages/aws-cdk-lib/aws-events-targets/lib/log-group.ts b/packages/aws-cdk-lib/aws-events-targets/lib/log-group.ts
index 4e8850fdd4fe8..42ad45dae5204 100644
--- a/packages/aws-cdk-lib/aws-events-targets/lib/log-group.ts
+++ b/packages/aws-cdk-lib/aws-events-targets/lib/log-group.ts
@@ -146,7 +146,7 @@ export class CloudWatchLogGroup implements events.IRuleTarget {
       if (typeof(resolvedTemplate) === 'string') {
         // need to add the quotes back to the string so that we can parse the json
         // '{"timestamp": <time>}' -> '{"timestamp": "<time>"}'
-        const quotedTemplate = resolvedTemplate.replace(new RegExp('(\<.*?\>)', 'g'), '"$1"');
+        const quotedTemplate = resolvedTemplate.replace(new RegExp('(<[^<>]*?>)', 'g'), '"$1"');
         try {
           const inputTemplate = JSON.parse(quotedTemplate);
           const inputTemplateKeys = Object.keys(inputTemplate);
diff --git a/packages/aws-cdk-lib/core/lib/cfn-mapping.ts b/packages/aws-cdk-lib/core/lib/cfn-mapping.ts
index d64b9272f1db3..ccfaa0312e937 100644
--- a/packages/aws-cdk-lib/core/lib/cfn-mapping.ts
+++ b/packages/aws-cdk-lib/core/lib/cfn-mapping.ts
@@ -53,6 +53,10 @@ export class CfnMapping extends CfnRefElement {
    * Sets a value in the map based on the two keys.
    */
   public setValue(key1: string, key2: string, value: any) {
+    if ([key1, key2].some(k => ['__proto__', 'constructor'].includes(k))) {
+      throw new Error('Cannot use \'__proto__\' or \'constructor\' as keys');
+    }
+
     this.validateAlphanumeric(key2);
 
     if (!(key1 in this.mapping)) {
diff --git a/packages/aws-cdk-lib/core/lib/cfn-resource.ts b/packages/aws-cdk-lib/core/lib/cfn-resource.ts
index ad8435951c416..c6c069f27e71f 100644
--- a/packages/aws-cdk-lib/core/lib/cfn-resource.ts
+++ b/packages/aws-cdk-lib/core/lib/cfn-resource.ts
@@ -651,6 +651,10 @@ function deepMerge(target: any, ...sources: any[]) {
     }
 
     for (const key of Object.keys(source)) {
+      if (key === '__proto__' || key === 'constructor') {
+        continue;
+      }
+
       const value = source[key];
       if (typeof(value) === 'object' && value != null && !Array.isArray(value)) {
         // if the value at the target is not an object, override it with an
diff --git a/packages/aws-cdk-lib/core/lib/context-provider.ts b/packages/aws-cdk-lib/core/lib/context-provider.ts
index d0e79fc02c7fb..764c05fd947fd 100644
--- a/packages/aws-cdk-lib/core/lib/context-provider.ts
+++ b/packages/aws-cdk-lib/core/lib/context-provider.ts
@@ -137,7 +137,7 @@ function extractProviderError(value: any): string | undefined {
  * than that \ is going to lead to quoting hell when the keys are stored in JSON.
  */
 function colonQuote(xs: string): string {
-  return xs.replace('$', '$$').replace(':', '$:');
+  return xs.replace(/\$/g, '$$').replace(/:/g, '$:');
 }
 
 function propsToArray(props: {[key: string]: any}, keyPrefix = ''): string[] {
diff --git a/packages/aws-cdk-lib/core/test/validation/validation.test.ts b/packages/aws-cdk-lib/core/test/validation/validation.test.ts
index fec0464668614..45e347422b300 100644
--- a/packages/aws-cdk-lib/core/test/validation/validation.test.ts
+++ b/packages/aws-cdk-lib/core/test/validation/validation.test.ts
@@ -771,7 +771,7 @@ const validationReport = (data: ValidationReportData[]) => {
         expect.stringMatching(new RegExp(`Plugin: ${d.pluginName}`)),
         expect.stringMatching(new RegExp(`Version: ${d.version ?? 'N/A'}`)),
         expect.stringMatching(new RegExp(`Status: ${d.status}`)),
-        expect.stringMatching(new RegExp('\(Violations\)')),
+        expect.stringMatching(new RegExp('\\(Violations\\)')),
         title,
         ...d.severity ? [expect.stringMatching(new RegExp(`Severity: ${d.severity}`))] : [],
         expect.stringMatching(new RegExp('  Occurrences:')),
diff --git a/packages/aws-cdk/lib/import.ts b/packages/aws-cdk/lib/import.ts
index e90b28e50f551..f90e9853fb8a7 100644
--- a/packages/aws-cdk/lib/import.ts
+++ b/packages/aws-cdk/lib/import.ts
@@ -293,7 +293,7 @@ export class ResourceImporter {
         const defaultValue = typeof resourceProps[idProp] ?? '';
 
         const prompt = [
-          promptPattern.replace(/%/, chalk.blue(idProp)),
+          promptPattern.replace(/%/g, chalk.blue(idProp)),
           defaultValue
             ? `[${defaultValue}]`
             : '(empty to skip)',
diff --git a/packages/aws-cdk/lib/util/objects.ts b/packages/aws-cdk/lib/util/objects.ts
index c372152a2cc5f..de582d11bd3d9 100644
--- a/packages/aws-cdk/lib/util/objects.ts
+++ b/packages/aws-cdk/lib/util/objects.ts
@@ -115,6 +115,10 @@ export function deepSet(x: any, path: string[], value: any) {
 export function deepMerge(...objects: Array<Obj<any> | undefined>) {
   function mergeOne(target: Obj<any>, source: Obj<any>) {
     for (const key of Object.keys(source)) {
+      if (key === '__proto__' || key === 'constructor') {
+        continue;
+      }
+
       const value = source[key];
 
       if (isObject(value)) {
diff --git a/packages/aws-cdk/test/commands/migrate.test.ts b/packages/aws-cdk/test/commands/migrate.test.ts
index 0b40011348e6f..111ef36c2aa1a 100644
--- a/packages/aws-cdk/test/commands/migrate.test.ts
+++ b/packages/aws-cdk/test/commands/migrate.test.ts
@@ -157,7 +157,7 @@ describe('Migrate Function Tests', () => {
 
     // Replaced stack file is referenced correctly in app file
     const app = fs.readFileSync(path.join(workDir, 'GoodJava', 'src', 'main', 'java', 'com', 'myorg', 'GoodJavaApp.java'), 'utf8').split('\n');
-    expect(app.map(line => line.match('public class GoodJavaApp \{')).filter(line => line).length).toEqual(1);
+    expect(app.map(line => line.match('public class GoodJavaApp {')).filter(line => line).length).toEqual(1);
     expect(app.map(line => line.match(/        new GoodJavaStack\(app, "GoodJava", StackProps.builder()/)).filter(line => line).length).toEqual(1);
 
     // Replaced stack file is correctly generated
diff --git a/packages/cdk-assets/lib/private/shell.ts b/packages/cdk-assets/lib/private/shell.ts
index ba7837f49810e..5e27452f98bab 100644
--- a/packages/cdk-assets/lib/private/shell.ts
+++ b/packages/cdk-assets/lib/private/shell.ts
@@ -107,7 +107,7 @@ function hasAnyChars(...chars: string[]): (x: string) => boolean {
  */
 function posixEscape(x: string) {
   // Turn ' -> '"'"'
-  x = x.replace("'", "'\"'\"'");
+  x = x.replace(/'/g, "'\"'\"'");
   return `'${x}'`;
 }
 
diff --git a/tools/@aws-cdk/cdk-build-tools/lib/os.ts b/tools/@aws-cdk/cdk-build-tools/lib/os.ts
index 8f37a96c1295f..2af5c1ac08376 100644
--- a/tools/@aws-cdk/cdk-build-tools/lib/os.ts
+++ b/tools/@aws-cdk/cdk-build-tools/lib/os.ts
@@ -107,7 +107,7 @@ function hasAnyChars(...chars: string[]): (x: string) => boolean {
  */
 function posixEscape(x: string) {
   // Turn ' -> '"'"'
-  x = x.replace("'", "'\"'\"'");
+  x = x.replace(/'/g, "'\"'\"'");
   return `'${x}'`;
 }
 
diff --git a/tools/@aws-cdk/pkglint/lib/rules.ts b/tools/@aws-cdk/pkglint/lib/rules.ts
index 08424c8c8e8df..a6da50be7a4ac 100644
--- a/tools/@aws-cdk/pkglint/lib/rules.ts
+++ b/tools/@aws-cdk/pkglint/lib/rules.ts
@@ -1857,7 +1857,7 @@ function isIncludedInMonolith(pkg: PackageJson): boolean {
 }
 
 function beginEndRegex(label: string) {
-  return new RegExp(`(<\!--BEGIN ${label}-->)([\s\S]+)(<\!--END ${label}-->)`, 'm');
+  return new RegExp(`(<\!--BEGIN ${label}-->)([\\s\\S]+)(<\!--END ${label}-->)`, 'm');
 }
 
 function readIfExists(filename: string): string | undefined {