Protocol Vulnerabilities

This is an academic survey (not an active exploit) analyzing how existing agent-security weaknesses become far more dangerous when AI agents use MCP tools and skills to sign and execute transactions on public blockchains. The authors argue that irreversibility, private-key signing authority, autonomous operation, and multi-step transaction composition turn normally recoverable agent failures into permanent financial loss, and find current defenses stop fewer than 30% of attacks. Since this is a research synthesis rather than a disclosed vulnerability or in-the-wild attack, severity is rated medium/informational for defenders rather than critical.

Updated Aug 19, 2026

An unauthenticated SSRF vulnerability exists in MLflow's webhook test endpoint that allows attackers to bypass URL validation using HTTP redirects. Attackers can craft a webhook pointing to a benign-looking URL that redirects to internal services or cloud metadata endpoints, then retrieve the response including sensitive credentials. This affects any AI agent or ML pipeline built on vulnerable MLflow versions, exposing cloud infrastructure secrets.

Updated Aug 18, 2026 · CVSS 9.3

The CKAN MCP Server had a flaw where request parameters were serialized into cache keys using unescaped delimiter characters (&, =, |), allowing different logical queries to produce identical cache keys. An attacker could exploit this collision to poison the shared cache with attacker-controlled data that gets served back to a victim making a distinct, legitimate query.

Updated Aug 15, 2026 · CVSS 6.5

An MCP server (mcp-dominican-layer) exposes a PDF-parsing tool that accepts a remote URL without adequate validation, allowing an attacker to force the server to make arbitrary outbound requests (SSRF). This could be used to probe internal networks, hit cloud metadata endpoints, or interact with internal services reachable from the MCP host. The vendor has not responded to the disclosure and a public exploit exists, increasing near-term risk for any deployment using this component.

Updated Aug 14, 2026 · CVSS 6.3

An MCP server component (mcp-rdf-explorer 1.0.0) contains a server-side request forgery vulnerability in its explore_url tool function, allowing a remote attacker to make the server issue arbitrary HTTP requests by manipulating the url argument. A public exploit exists and the vendor has not responded to disclosure, leaving the issue unpatched.

Updated Aug 14, 2026 · CVSS 7.3

Researchers found that encrypted chain-of-thought blocks returned by major LLM providers (Anthropic, OpenAI, Google) are interchangeable across sessions, users, and models within the same provider, allowing a weaker model to be tricked into decrypting and outputting another model's private reasoning in plaintext. This enables extraction of proprietary reasoning, recovery of PII/credentials from publicly shared session logs, exposure of hazardous content hidden in reasoning, and invisible prompt injection into agentic pipelines. This is a genuine, disclosed architectural vulnerability with demonstrated real-world impact.

Updated Aug 11, 2026

The Meta Ads MCP server (prior to v1.0.109) fails to enforce authentication on Streamable HTTP requests, allowing any network-reachable caller to invoke privileged Meta Ads tool handlers. When these calls fail downstream, the server leaks the operator's Meta access token by embedding it in the raw request URL returned within the JSON-RPC error response, giving attackers full account takeover potential.

Updated Aug 8, 2026 · CVSS 9.1

A server-side request forgery (SSRF) vulnerability was found in MissionSquad mcp-api versions up to 1.11.9, specifically in the dynamic client registration handling code. A remote attacker can exploit this flaw to make the MCP server issue unauthorized requests to internal or arbitrary network destinations. The issue is fixed in version 1.11.10.

Updated Aug 7, 2026 · CVSS 6.3

IBM Langflow's implementation of the MCP resources/read request fails to sanitize file paths, allowing an attacker to use URL-encoded path traversal sequences to read arbitrary files on the server. This exposes sensitive data including other users' uploaded documents, the JWT signing secret, the SQLite database, and environment variables, which could enable full account takeover or further compromise.

Updated Aug 5, 2026 · CVSS 6.5

IBM Langflow versions 1.0.0 through 1.10.3 have an authentication bypass in the MCP composer endpoint that occurs when the default setting mcp_composer_enabled=true is combined with OAuth-based project authentication. This allows an attacker to circumvent intended access controls on MCP composer functionality, potentially gaining unauthorized access to project resources or agent workflows.

Updated Aug 5, 2026 · CVSS 7.5

This is a large-scale academic security assessment (not an active exploit report) finding that thousands of publicly reachable Model Context Protocol (MCP) servers are deployed with weak or absent security controls. Researchers found high rates of missing authentication, exposed shell execution tools, SSRF against cloud metadata endpoints, SQL injection, and prompt template injection across hundreds of confirmed production servers. The findings represent systemic ecosystem-wide risk rather than a single vulnerability in one product.

Updated Aug 4, 2026

This is an academic measurement study of the official MCP registry, not an active exploit or vulnerability disclosure. The researchers show that periodic, drift-ranked re-auditing of server descriptions poorly covers actual description changes over time, and recommend content-hash-based revalidation instead. No attack technique, malicious payload, or exploited weakness is described.

Updated Aug 4, 2026

better-auth's OIDC provider and MCP plugin fail to validate the URI scheme of registered OAuth redirect_uris, allowing an attacker to register a javascript: URI that gets echoed back to the consent page. If the consent UI navigates to this URI unsafely, attacker JavaScript executes in the authorization server's origin, potentially hijacking victim sessions. This is a classic web input-validation flaw made newly relevant because it affects the auth layer underlying MCP server deployments, extending its blast radius to agent tool-authorization flows.

Updated Aug 1, 2026 · CVSS 7.2

The MCP Ruby SDK's StreamableHTTP transport failed to bind session IDs to the client/owner that created them, so anyone who obtains a valid session ID (via theft, leakage in logs/URLs, or interception) could issue tools/call requests that execute with the victim's authenticated session context. This allows an attacker to impersonate a legitimate user or agent and trigger tool actions on their behalf without needing credentials.

Updated Jul 30, 2026

The MCP Ruby SDK's HTTP transport failed to validate Host or Origin headers before version 0.23.0, allowing a malicious website to use DNS rebinding to reach a locally running MCP server from a victim's browser. This lets an attacker invoke tools exposed by the local MCP server without authorization, effectively bypassing the same-origin trust boundary that localhost services normally rely on.

Updated Jul 30, 2026

The alibabacloud-rds-openapi-mcp-server binds its MCP endpoint to all network interfaces by default, allowing any network-adjacent attacker to reach and invoke its exposed tools without proper access restriction. This is a configuration/deployment flaw rather than a novel exploit technique, but it can let unauthorized parties trigger RDS-related MCP tools if the server is reachable. Severity is moderate given the CVSS score of 5.8 and the dependency on network exposure and lack of authentication for actual exploitation.

Updated Jul 28, 2026 · CVSS 5.8

Researchers identify 33 protocol-level vulnerabilities across three leading agentic commerce platforms, achieving a 100% attack success rate independent of the AI model used, with three vulnerabilities chaining into a full payment hijack. This is a research paper (not an active exploit in the wild) demonstrating that agent-to-commerce-service protocols, not model behavior, are the primary structural risk in agentic payment systems.

Updated Jul 27, 2026

A vulnerability in NanoClaw's MCP Server Approval component allows a local attacker to bypass authorization checks in the createChatSdkBridge.setup function, potentially approving or manipulating MCP server connections without proper consent. The flaw requires local access and has a public exploit available, but the vendor has not yet responded to the disclosure. Severity is moderate due to the local attack vector constraint, though the improper authorization could undermine trust in MCP server approval workflows.

Updated Jul 26, 2026 · CVSS 5.3

Jan's local API server (through v0.8.4) mishandles trusted host configuration, replacing user-defined allowed origins with a wildcard that reflects any origin while still allowing credentials. This lets a network-adjacent or DNS-rebinding attacker reach the unauthenticated OpenAI-compatible API to run inference, enumerate models, invoke MCP tools, and read cross-origin responses. Fixed in commit 3e1c1e7; upgrade is the primary remediation.

Updated Jul 24, 2026 · CVSS 6.3

This is defensive academic research, not an active exploit or new vulnerability disclosure. The paper proposes ChainWatch, a detection framework using a kill-chain model and Hidden Markov Models to spot malicious sequences of otherwise-benign MCP tool calls that evade per-call security checks. It confirms a known class of risk (composable multi-step attacks in MCP agent systems) but the artifact itself is a defense, so severity is low from a threat-alert perspective.

Updated Jul 23, 2026