Top Vulnerabilities in MCP Servers & How FinTechs Can Protect Themselves

TL; DR

• FinTech's MCP servers are valuable targets because they store sensitive financial information and work with AI models that are used to find fraud, process loans, and help customers.
• The most common vulnerabilities include prompt injection, inadequately configured network exposure, unpatched dependencies (CVE-2025-6514), insecure API authentication, and data leakage from poor context handling.
• Mitigation measures include several layers of defence, automated monitoring with MCP security tools, regular audits, input validation, and working with professionals like Codiste for security that is particular to FinTech.
• Proactive security is a business-critical expenditure because ignoring MCP vulnerabilities results in breaches, regulatory fines, and irreversible brand damage.
• Any FinTech company that runs MCP servers in production must have a zero-trust architecture, secret management, and network segmentation.

MCP servers are now the backbone of AI-driven FinTech infrastructure, but here's the thing: they're also becoming a favorite target for attackers. In early 2025, the CVE-2025-6514 vulnerability in MCP-remote made it possible for thousands of servers to run code from a distance. This made Docker send urgent warnings about MCP security holes caused by containers that weren't set up correctly. If you're running MCP servers to power conversational AI, transaction monitoring, or fraud detection, you're sitting on a goldmine of sensitive financial data that bad actors want.

What this really means is that the MCP vulnerability isn't a theoretical risk anymore. FinTech companies are racing to patch systems, but many don't even know where to start. This guide breaks down the most critical MCP server vulnerabilities in FinTech, what makes them dangerous, and how to lock down your infrastructure before the next breach hits the headlines.

Why MCP Servers Are So Critical in Banking AI

MCP (Model Context Protocol) servers connect AI models to outside data sources, APIs, or applications that users can see. They are crucial for making real-time decisions in FinTech, such as processing loan applications, identifying fraudulent transactions, or directing customer care enquiries to the appropriate division. The difficulty is that MCP servers deal with a lot of sensitive information and sometimes work with older systems that weren't designed with today's security standards in mind.

Banking AI systems leverage MCP servers to preserve conversational context throughout multi-turn customer interactions, retain transaction records, and retrieve information from internal databases without compromising sensitive credentials.

When these systems are hacked, attackers can do more than just get into one account. They can move around your whole infrastructure, steal consumer PII, or change AI outputs to authorize fake transactions.

In FinTech, the stakes are higher since regulatory sanctions (such GDPR fines or PCI-DSS violations) can ruin a company's finances, and customers lose faith as soon as a breach becomes public.

The Most Dangerous MCP Vulnerabilities in FinTech

Let's dissect it. In order of exploitability and probable harm, these are the MCP security vulnerabilities that FinTech teams now need to fix.

Insecure API Authentication and Authorization

Most MCP server security failures start here. MCP servers use OAuth credentials or API keys to permit queries from outside tools or AI models. However, the issue is that developers usually choose scopes that are too broad and provide access to more data than they require, hardcode API keys into configuration files, or place them in easily visible environment variables.

If a hacker gets into your GitHub repository or a developer's computer that has been hacked, they can use these credentials to pretend to be trustworthy services. 

The Anthropic MCP vulnerability reports from the first quarter of 2025 showed that open API keys let anyone who shouldn't have access to client discussion logs, which included transaction data and account numbers. This is not simply a data leak in the FinTech industry; it's a compliance disaster. You could be in danger if your MCP server can't enforce least-privilege access or rotate credentials automatically.

What to do: Use short-lived tokens that automatically rotate, secret management solutions like HashiCorp Vault or AWS Secrets Manager, and role-based access control (RBAC) at the API gateway level. Never trust environment variables alone; encrypt secrets at rest and in transit.

Remote Code Execution via Unpatched Dependencies

The MCP-remote CVE-2025-6514 vulnerability was a wake-up call. Using a deserialization flaw in a widely used Python program, this vulnerability allowed attackers to execute any code they wanted on MCP servers. The dilemma was exacerbated by the fact that a number of FinTech companies were utilizing outdated MCP frameworks since they prioritized reliability over improvements. What went down? Attackers might place malware on a computer, steal data, or even change the outputs of an AI model so that fake wire transfers go through.

Docker warns that MCP security issues are especially common in containerized environments, as teams obtain base images from public registries without verifying their integrity. It may take months for a backdoored MCP server and a poisoned Docker image to be discovered in your environment.

What to do: Set up a patch management routine, sign up for security alerts for your MCP framework (like Anthropic's GitHub), and check container images with tools like Trivy or Snyk before you use them. Isolate MCP servers on distinct network segments to stop lateral movement in the case of a hack.

Data Leakage Through Improper Context Handling

MCP servers maintain context across AI interactions, which is great for user experience but terrible for security if mishandled. The MCP security concern here is that context frequently contains sensitive data such as account balances, SSNs, or transaction history, which developers sometimes log for debugging or save in unencrypted databases. If an attacker gets into your logging system or a poorly protected S3 bucket, they can put together all of your customers' interactions.

Due to the context store's lack of encryption at rest, a misconfigured MCP server was able to leak project data, including customer lists and financial estimates, as demonstrated in the Asana MCP vulnerability case study from late 2024. In FinTech, this could include showing off customer portfolios, trading algorithms, or internal risk models.

What to do: Use AES-256 to encrypt context stores, ephemeral storage when possible (such that context is destroyed when sessions finish), and redact personally identifiable information from logs. Look for weak outgoing traffic patterns using data loss prevention (DLP) methods.

Insufficient Input Validation and Prompt Injection

This is the silent killer of MCP security. MCP servers take input from users, APIs, or AI models and pass it to backend systems. If input isn't validated, attackers can inject malicious prompts or payloads that manipulate AI behavior or bypass security controls. For example, a crafted input could trick an AI-powered loan approval system into ignoring credit score thresholds, or a prompt injection could extract internal system prompts that reveal business logic.

FinTech companies using MCP servers for customer-facing chatbots are especially at risk. An attacker may send a well-worded query that makes the AI give away another customer's transaction history or run SQL commands on the database.

What to do: To make sure AI replies don't leak private information, sanitize all inputs using stringent whitelisting (not blacklisting), put in place prompt firewalls that identify injection attempts, and employ output validation. NeMo Guardrails and LangKit are two useful tools.

Misconfigured Network Exposure and Lack of Segmentation

Too many MCP server vulnerabilities in FinTech boil down to basic network hygiene. When MCP servers are set up, they often come with default settings that make administrative interfaces available to the public internet. They may also be put in the same VLAN as web servers that users can see. Because of this, attackers can easily target them by looking for open ports or taking advantage of known weaknesses in nearby systems.

The MCP vulnerabilities GitHub issue tracker is full of reports where developers forgot to disable debug endpoints or left admin panels accessible without authentication. In one situation, a FinTech startup's MCP server was hacked because it shared a subnet with a WordPress site that was easy to hack. The hacker then moved on from there.

What to do: Use network segmentation to separate MCP servers from other services, place them behind firewalls with stringent ingress/egress rules, and require VPN access for administrative duties. Turn down ports and services that aren't needed and run regular penetration testing to find any problems with the setup.

Read more:

• Using MCP Server to Bridge Blockchain & AI in Fintech Platforms
• 7 Reasons Python Is Perfect for Building MCP Servers
• 5 Key Use Cases of MCP in Fintech: Payments, Lending, KYC & More
• What is the Difference Between A2A vs MCP?

MCP Security Best Practices for FinTech

Now that we've covered the vulnerabilities, here's your playbook for hardening MCP server security in a FinTech context. These are the necessities for maintaining compliance and safeguarding client information; they are not extras.

Build a Multi-Layered Defense

Think of MCP security like an onion. You need more than one layer so that attackers can't get to the core right away if one fails. Protect at the network level first (firewalls, IDS/IPS), then at the application level (API authentication, input validation), and lastly at the data level (encryption, tokenization). Even if a request comes from inside your network, you should use a zero-trust model to check it.

Automate Security Monitoring and Incident Response

It's not enough to do manual security audits. Use MCP security tools that keep an eye on server activity all the time for strange things, like unusual API request patterns, attempts to get more access, or data exfiltration. Splunk, Datadog, and Wazuh are examples of tools that can consume MCP server logs and send out alarms when something seems strange. Configure automated playbooks in your SIEM to automatically revoke suspect API keys or quarantine compromised servers.

Conduct Regular Security Audits and Penetration Testing

Your MCP security checklist should include quarterly audits where you review access logs, test authentication mechanisms, and verify that patches are applied. Hire an external security firm to conduct penetration testing on your MCP infrastructure that mimics real-world assaults. These exercises often find things that people don't know about, like test servers that have been neglected or IAM policies that are too open.

Train Your Team on MCP-Specific Threats

There are several weaknesses in MCP cybersecurity that developers and DevOps engineers need to know about. Conduct training sessions on MCP framework installation, fast injection defenses, and secure code. Incorporate security into your CI/CD process by requiring automated scans and code reviews prior to deployment.

Conclusion: Partner with Experts Who Understand FinTech Security

It's hard to establish a safe MCP infrastructure, especially when you have to obey the regulations and come up with innovative concepts at the same time. This is when it makes sense to work with a firm like Codiste that knows a lot about this. Codiste understands a lot about MCP security in banking and can help you make systems that are robust enough to follow the rules set by PCI-DSS, SOC 2, and GDPR. They'll conduct a full security assessment of your MCP servers, implement hardening measures, and set up monitoring that actually works. If you're serious about safeguarding your FinTech infrastructure, you'll require an experienced staff.