Vulnerability Database

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Total vulnerabilities in the database

CVE-2026-46555

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

WhatsApp MCP Server is a Model Context Protocol (MCP) server for WhatsApp, enabling Claude to read and send WhatsApp messages. Prior to version 0.2.1, the whatsapp-bridge HTTP API listens on 127.0.0.1:8080 without authentication and without Host header validation, and the /api/send endpoint accepts an absolute media_path parameter without confining it to a safe directory. Combined, these issues allow any local process running as the same user as the bridge to send WhatsApp messages from the paired account without authorization; the same caller to read arbitrary files readable by the user (e.g. SSH private keys, browser session data, source code, dotfiles) and exfiltrate them as WhatsApp document attachments; and/or a remote attacker to trigger the same operations via DNS rebinding from a webpage the user visits, since no Host header validation is performed. In MCP environments, "local caller" extends beyond processes the user explicitly launched — sibling MCP servers, IDE extensions, and tool-triggered flows running in the user's session can act as the effective caller. This issue is fixed in whatsapp-mcp v0.2.1 and corresponding Docker images / release artifacts. Users should upgrade immediately. The fix introduces bearer token authentication on the bridge HTTP API (configured via environment variable, required on all requests, validated with constant-time comparison); host header allow-list validation to prevent DNS rebinding; and confinement of media_path to a configured directory, with rejection of absolute paths outside the root and path traversal sequences. This is a breaking change for clients of the bridge API. For users who cannot immediately upgrade: Stop the bridge, or block loopback access to port 8080, when the bridge is not actively in use; avoid running the bridge alongside untrusted MCP servers, browser extensions, or other untrusted local processes; avoid browsing untrusted sites while the bridge is running (DNS rebinding mitigation); and/or run the bridge under a dedicated user account or in a sandbox/container with no access to sensitive files.

  • Published: Jul 20, 2026
  • Updated: Jul 21, 2026
  • CVE: CVE-2026-46555
  • Severity: High
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: High
  • Score: 7.7
  • AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.