Path Traversal in WhatsApp MCP Server (CVE-2026-46555)
Summary
Path traversal in WhatsApp MCP Server (CVE-2026-46555). Confidential information can be exposed externally. Exploitable via Host header.
Original description
The description as published by the source.
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 co…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-46555 has been found in WhatsApp MCP Server.
Attackers can target a specific entry point like Host header over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.7/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "WhatsApp MCP Server CVE-2026-46555" on the vendor's site.
CVE-2026-46555 (WhatsApp MCP Server) — CWE-22 / CVSS v3 7.7
Attack vector: local / unauthenticated / no user interaction
Attack surface: Host header / media_path
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Path traversal (CWE-22) exists in WhatsApp MCP Server. Attackers reach the vulnerable code path via Host header without authentication.
Check the vendor advisory for the affected versions of WhatsApp MCP Server. Attack surface: Host header / media_path.
Severity: High (CVSS 7.7/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで WhatsApp MCP Server を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- web github.com
- web github.com