diff --git a/eslint.config.mjs b/eslint.config.mjs
index 0f2e41f4..4100420b 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -9,7 +9,6 @@ export default tseslint.config(
   },
   {
     rules: {
-        "@typescript-eslint/no-explicit-any": "off",
         "@typescript-eslint/no-extraneous-class": ["error", {
             allowWithDecorator: true
         }]
diff --git a/src/auth/auth.guard.ts b/src/auth/auth.guard.ts
index be3c7b3a..1a4e707b 100644
--- a/src/auth/auth.guard.ts
+++ b/src/auth/auth.guard.ts
@@ -72,9 +72,9 @@ export class AuthGuard implements CanActivate {
     );
 
     try {
-      return await this.authService.validateToken(token, processorType);
+      return !!(await this.authService.validateToken(token, processorType));
     } catch {
-      return this.authService.validateToken(token, JwtProcessorType.BEARER);
+      return !!(await this.authService.validateToken(token, JwtProcessorType.BEARER));
     }
   }
 
diff --git a/src/auth/auth.service.spec.ts b/src/auth/auth.service.spec.ts
index 0b6b5d19..002d3b7f 100644
--- a/src/auth/auth.service.spec.ts
+++ b/src/auth/auth.service.spec.ts
@@ -30,6 +30,7 @@ describe('AuthService', () => {
         AuthService,
         {
           provide: EntityManager,
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
           useFactory: () => new (EntityManager as any)(),
         },
         {
diff --git a/src/auth/auth.service.ts b/src/auth/auth.service.ts
index 5ae1688d..9ac7773f 100644
--- a/src/auth/auth.service.ts
+++ b/src/auth/auth.service.ts
@@ -121,7 +121,7 @@ export class AuthService {
     );
   }
 
-  validateToken(token: string, processor: JwtProcessorType): Promise<any> {
+  validateToken(token: string, processor: JwtProcessorType): Promise<unknown> {
     return this.processors.get(processor).validateToken(token);
   }
 
diff --git a/src/auth/jwt/jwt.header.ts b/src/auth/jwt/jwt.header.ts
index 2c251593..4c176de0 100644
--- a/src/auth/jwt/jwt.header.ts
+++ b/src/auth/jwt/jwt.header.ts
@@ -1,7 +1,9 @@
+import type { JWK } from 'jose';
+
 export class JwtHeader {
   alg: 'HS256' | 'HS384' | 'HS512' | 'RS256' | 'none';
   jku?: string;
-  jwk?: any;
+  jwk?: JWK;
   kid?: string;
   x5u?: string;
   x5c?: string[];
diff --git a/src/auth/jwt/jwt.token.bearer.processor.ts b/src/auth/jwt/jwt.token.bearer.processor.ts
index 045eded8..f23331b2 100644
--- a/src/auth/jwt/jwt.token.bearer.processor.ts
+++ b/src/auth/jwt/jwt.token.bearer.processor.ts
@@ -12,7 +12,7 @@ export class JwtBearerTokenProcessor extends JwtTokenProcessor {
     super(new Logger(JwtBearerTokenProcessor.name));
   }
 
-  async validateToken(token: string): Promise<any> {
+  async validateToken(token: string): Promise<unknown> {
     const [header, payload] = this.parse(token);
     if (!header || !payload) {
       this.log.debug(`Invalid JWT token. parse() failure.`);
@@ -56,7 +56,7 @@ export class JwtBearerTokenProcessor extends JwtTokenProcessor {
     }
   }
 
-  private async decodeAndVerifyToken(token: string, kid: string): Promise<any> {
+  private async decodeAndVerifyToken(token: string, kid: string): Promise<unknown> {
     try {
       return await this.keyCloakService.verifyToken(token, kid);
     } catch (e) {
diff --git a/src/auth/jwt/jwt.token.processor.ts b/src/auth/jwt/jwt.token.processor.ts
index 81728178..d69f129f 100644
--- a/src/auth/jwt/jwt.token.processor.ts
+++ b/src/auth/jwt/jwt.token.processor.ts
@@ -10,7 +10,7 @@ export abstract class JwtTokenProcessor {
     this.log = log;
   }
 
-  protected parse(token: string): [header: JwtHeader, payload: any] {
+  protected parse(token: string): [header: JwtHeader, payload: unknown] {
     this.log.debug('Call parse');
 
     const parts = token.split('.');
@@ -23,7 +23,7 @@ export abstract class JwtTokenProcessor {
 
     const payloadStr = Buffer.from(parts[1], 'base64').toString('ascii');
     this.log.debug(`Jwt token (None alg) payload is ${payloadStr}`);
-    const payload: any = JSON.parse(payloadStr);
+    const payload = JSON.parse(payloadStr);
 
     return [header, payload];
   }
@@ -50,7 +50,7 @@ export abstract class JwtTokenProcessor {
     return key;
   }
 
-  abstract validateToken(token: string): Promise<any>;
+  abstract validateToken(token: string): Promise<unknown>;
 
   abstract createToken(payload: unknown): Promise<string>;
 }
diff --git a/src/auth/jwt/jwt.token.with.hmac.keys.processor.ts b/src/auth/jwt/jwt.token.with.hmac.keys.processor.ts
index 72f5abe3..444771e1 100644
--- a/src/auth/jwt/jwt.token.with.hmac.keys.processor.ts
+++ b/src/auth/jwt/jwt.token.with.hmac.keys.processor.ts
@@ -7,7 +7,7 @@ export class JwtTokenWithHMACKeysProcessor extends JwtTokenProcessor {
     super(new Logger(JwtTokenWithHMACKeysProcessor.name));
   }
 
-  async validateToken(token: string): Promise<any> {
+  async validateToken(token: string): Promise<unknown> {
     this.log.debug('Call validateToken');
 
     return decode(token, this.publicKey, false, 'HS256');
diff --git a/src/auth/jwt/jwt.token.with.jku.processor.ts b/src/auth/jwt/jwt.token.with.jku.processor.ts
index c9d35a6c..c98f0b14 100644
--- a/src/auth/jwt/jwt.token.with.jku.processor.ts
+++ b/src/auth/jwt/jwt.token.with.jku.processor.ts
@@ -12,7 +12,7 @@ export class JwtTokenWithJKUProcessor extends JwtTokenProcessor {
     super(new Logger(JwtTokenWithJKUProcessor.name));
   }
 
-  async validateToken(token: string): Promise<any> {
+  async validateToken(token: string): Promise<unknown> {
     this.log.debug('Call validateToken');
     const [header, payload] = this.parse(token);
 
diff --git a/src/auth/jwt/jwt.token.with.jwk.processor.ts b/src/auth/jwt/jwt.token.with.jwk.processor.ts
index b01ffb91..a9a4eb2b 100644
--- a/src/auth/jwt/jwt.token.with.jwk.processor.ts
+++ b/src/auth/jwt/jwt.token.with.jwk.processor.ts
@@ -7,7 +7,7 @@ export class JwtTokenWithJWKProcessor extends JwtTokenProcessor {
     super(new Logger(JwtTokenWithJWKProcessor.name));
   }
 
-  async validateToken(token: string): Promise<any> {
+  async validateToken(token: string): Promise<unknown> {
     this.log.debug('Call validateToken');
     const [header, payload] = this.parse(token);
 
diff --git a/src/auth/jwt/jwt.token.with.rsa.keys.processor.ts b/src/auth/jwt/jwt.token.with.rsa.keys.processor.ts
index 97024cf7..28f47d07 100644
--- a/src/auth/jwt/jwt.token.with.rsa.keys.processor.ts
+++ b/src/auth/jwt/jwt.token.with.rsa.keys.processor.ts
@@ -7,7 +7,7 @@ export class JwtTokenWithRSAKeysProcessor extends JwtTokenProcessor {
     super(new Logger(JwtTokenWithRSAKeysProcessor.name));
   }
 
-  async validateToken(token: string): Promise<any> {
+  async validateToken(token: string): Promise<unknown> {
     this.log.debug('Call validateToken');
 
     const [header, payload] = this.parse(token);
diff --git a/src/auth/jwt/jwt.token.with.rsa.signature.keys.processor.ts b/src/auth/jwt/jwt.token.with.rsa.signature.keys.processor.ts
index c390e245..c9fc0bf5 100644
--- a/src/auth/jwt/jwt.token.with.rsa.signature.keys.processor.ts
+++ b/src/auth/jwt/jwt.token.with.rsa.signature.keys.processor.ts
@@ -7,7 +7,7 @@ export class JwtTokenWithRSASignatureKeysProcessor extends JwtTokenProcessor {
     super(new Logger(JwtTokenWithRSASignatureKeysProcessor.name));
   }
 
-  async validateToken(token: string): Promise<any> {
+  async validateToken(token: string): Promise<unknown> {
     this.log.debug('Call validateToken');
 
     return decode(token, this.publicKey, true, 'RS256');
diff --git a/src/auth/jwt/jwt.token.with.sql.kid.processor.ts b/src/auth/jwt/jwt.token.with.sql.kid.processor.ts
index ef893e31..71b843d1 100644
--- a/src/auth/jwt/jwt.token.with.sql.kid.processor.ts
+++ b/src/auth/jwt/jwt.token.with.sql.kid.processor.ts
@@ -13,7 +13,7 @@ export class JwtTokenWithSqlKIDProcessor extends JwtTokenProcessor {
     super(new Logger(JwtTokenWithSqlKIDProcessor.name));
   }
 
-  async validateToken(token: string): Promise<any> {
+  async validateToken(token: string): Promise<unknown> {
     this.log.debug('Call validateToken');
 
     const [header] = this.parse(token);
diff --git a/src/auth/jwt/jwt.token.with.weak.key.processor.ts b/src/auth/jwt/jwt.token.with.weak.key.processor.ts
index 6c24bfb8..30ae4689 100644
--- a/src/auth/jwt/jwt.token.with.weak.key.processor.ts
+++ b/src/auth/jwt/jwt.token.with.weak.key.processor.ts
@@ -7,7 +7,7 @@ export class JwtTokenWithWeakKeyProcessor extends JwtTokenProcessor {
     super(new Logger(JwtTokenWithWeakKeyProcessor.name));
   }
 
-  async validateToken(token: string): Promise<any> {
+  async validateToken(token: string): Promise<unknown> {
     this.log.debug('Call validateToken');
     return decode(token, this.key, false);
   }
diff --git a/src/auth/jwt/jwt.token.with.x5c.key.processor.ts b/src/auth/jwt/jwt.token.with.x5c.key.processor.ts
index c5090c5b..38b21dd0 100644
--- a/src/auth/jwt/jwt.token.with.x5c.key.processor.ts
+++ b/src/auth/jwt/jwt.token.with.x5c.key.processor.ts
@@ -7,7 +7,7 @@ export class JwtTokenWithX5CKeyProcessor extends JwtTokenProcessor {
     super(new Logger(JwtTokenWithX5CKeyProcessor.name));
   }
 
-  async validateToken(token: string): Promise<any> {
+  async validateToken(token: string): Promise<unknown> {
     this.log.debug('Call validateToken');
     const [header] = this.parse(token);
 
diff --git a/src/auth/jwt/jwt.token.with.x5u.key.processor.ts b/src/auth/jwt/jwt.token.with.x5u.key.processor.ts
index 90c30c28..30c6568d 100644
--- a/src/auth/jwt/jwt.token.with.x5u.key.processor.ts
+++ b/src/auth/jwt/jwt.token.with.x5u.key.processor.ts
@@ -11,7 +11,7 @@ export class JwtTokenWithX5UKeyProcessor extends JwtTokenProcessor {
     super(new Logger(JwtTokenWithX5UKeyProcessor.name));
   }
 
-  async validateToken(token: string): Promise<any> {
+  async validateToken(token: string): Promise<unknown> {
     this.log.debug('Call validateToken');
     const [header] = this.parse(token);
 
diff --git a/src/components/any-files.interceptor.ts b/src/components/any-files.interceptor.ts
index 6a014a2d..4c700b0f 100644
--- a/src/components/any-files.interceptor.ts
+++ b/src/components/any-files.interceptor.ts
@@ -12,8 +12,8 @@ import { FastifyReply, FastifyRequest } from 'fastify';
 export class AnyFilesInterceptor implements NestInterceptor {
   public async intercept(
     context: ExecutionContext,
-    next: CallHandler<any>,
-  ): Promise<Observable<any>> {
+    next: CallHandler<unknown>,
+  ): Promise<Observable<unknown>> {
     const req = context.switchToHttp().getRequest() as FastifyRequest;
     const res = context.switchToHttp().getResponse() as FastifyReply;
 
diff --git a/src/components/headers.configurator.interceptor.ts b/src/components/headers.configurator.interceptor.ts
index 9be12948..00cb78ce 100644
--- a/src/components/headers.configurator.interceptor.ts
+++ b/src/components/headers.configurator.interceptor.ts
@@ -25,7 +25,7 @@ export class HeadersConfiguratorInterceptor implements NestInterceptor {
   public static readonly COUNTER_COOKIE_NAME = 'bc-calls-counter';
   private readonly logger = new Logger(HeadersConfiguratorInterceptor.name);
 
-  intercept(context: ExecutionContext, next: CallHandler): Observable<any> {
+  intercept(context: ExecutionContext, next: CallHandler): Observable<unknown> {
     const req = this.getRequest(context);
 
     const cookies: string[] = req.headers.cookie
diff --git a/src/email/email.controller.ts b/src/email/email.controller.ts
index afcbc787..6a55e94b 100644
--- a/src/email/email.controller.ts
+++ b/src/email/email.controller.ts
@@ -84,9 +84,9 @@ export class EmailController {
     this.logger.debug(`Raw query ${rawQuery}`);
 
     // "Use" the status code
-    const uriParams: any = splitUriIntoParamsPPVulnerable(rawQuery);
+    const uriParams = splitUriIntoParamsPPVulnerable(rawQuery);
     if (uriParams?.status) {
-      responseJson.status = uriParams.status;
+      responseJson.status = uriParams.status as HttpStatus;
     }
 
     const mailSubject = `Support email regarding "${subject}"`;
@@ -118,8 +118,8 @@ export class EmailController {
     example: 'true',
     required: true,
   })
-  async getEmails(@Query('withSource') withSource: any) {
-    withSource = withSource === 'true';
+  async getEmails(@Query('withSource') withSourceStr: string) {
+    const withSource = withSourceStr === 'true';
 
     this.logger.log(`Getting Emails (withSource=${withSource})`);
     return await this.emailService.getEmails(withSource);
diff --git a/src/email/email.service.ts b/src/email/email.service.ts
index b3e99933..5986de0f 100644
--- a/src/email/email.service.ts
+++ b/src/email/email.service.ts
@@ -60,11 +60,11 @@ export class EmailService {
     to = to.replace('\n', '%0A');
     this.logger.debug(`Creating vulnerable mailOptions. "to" param is: ${to}`);
 
-    let parsedSubject: any = subject;
-    let parsedFrom: any = from;
-    let parsedTo: any = to;
-    let parsedCc: any = [];
-    let parsedBcc: any = [];
+    let parsedSubject: string | RegExpExecArray | null = subject;
+    let parsedFrom: string | RegExpExecArray | null = from;
+    let parsedTo: string | RegExpExecArray | null = to;
+    let parsedCc: string | RegExpExecArray | null = null;
+    let parsedBcc: string | RegExpExecArray | null = null;
 
     // This is intentional to support email injection
     if (
@@ -124,7 +124,7 @@ export class EmailService {
     return mailOptions;
   }
 
-  async getEmails(withSource): Promise<any> {
+  async getEmails(withSource): Promise<unknown> {
     this.logger.debug(`Fetching all emails from MailCatcher`);
 
     const emails = await axios
diff --git a/src/httpclient/httpclient.service.ts b/src/httpclient/httpclient.service.ts
index c204e7cd..afe5f4dc 100644
--- a/src/httpclient/httpclient.service.ts
+++ b/src/httpclient/httpclient.service.ts
@@ -22,7 +22,7 @@ export class HttpClientService {
 
   async post<T = unknown>(
     url: string,
-    data: any,
+    data: unknown,
     config?: AxiosRequestConfig,
   ): Promise<T> {
     const resp = await axios.post<T>(url, data, config);
diff --git a/src/utils/url.ts b/src/utils/url.ts
index 70a17133..6b502e8d 100644
--- a/src/utils/url.ts
+++ b/src/utils/url.ts
@@ -1,11 +1,11 @@
 // Taken from PortSwigger's prototype pollution labs
 // VULNERABLE TO PROTOTYPE POLLUTION!
-const splitUriIntoParamsPPVulnerable = (params, coerce = undefined) => {
+const splitUriIntoParamsPPVulnerable = (params, coerce = undefined): Record<string, unknown> => {
   if (params.charAt(0) === '?') {
     params = params.substring(1);
   }
 
-  const obj = {};
+  const obj: Record<string, unknown> = {};
   const coerce_types = { true: !0, false: !1, null: null };
 
   if (!params) {
@@ -21,6 +21,7 @@ const splitUriIntoParamsPPVulnerable = (params, coerce = undefined) => {
       let keys = key.split('][');
       let keys_last = keys.length - 1;
       let val;
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
       let cur: any = obj;
       let i = 0;
 
@@ -52,12 +53,13 @@ const splitUriIntoParamsPPVulnerable = (params, coerce = undefined) => {
             cur = cur[key] =
               i < keys_last
                 ? cur[key] ||
+                  // eslint-disable-next-line @typescript-eslint/no-explicit-any
                   (keys[i + 1] && isNaN(keys[i + 1] as any) ? {} : [])
                 : val;
           }
         } else {
           if (Object.prototype.toString.call(obj[key]) === '[object Array]') {
-            obj[key].push(val);
+            (obj[key] as unknown[]).push(val);
           } else if ({}.hasOwnProperty.call(obj, key)) {
             obj[key] = [obj[key], val];
           } else {