Raw vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-46555 is a high-severity Path Traversal (CWE-22) vulnerability in Verygoodplugins Whatsapp Mcp Server. Its CVSS base score is 7.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
This vulnerability is AI-related — categorised as AI Agent Protocols and Integrations; in the Protocol-Specific Risks risk domain.
The strongest mitigations our analysis identified map to AC-14 (Permitted Actions Without Identification or Authentication) and AC-3 (Access Enforcement) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-46037
Vulnerability Data
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…
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`/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.
- CWE(s)
AI Security AnalysisAI
- AI Category
- AI Agent Protocols and Integrations
- Risk Domain
- Protocol-Specific Risks
- OWASP Top 10 for LLMs 2025
- None mapped
- Classification Reason
- Matched keywords: mcp, model context protocol, mcp, claude, mcp, mcp, mcp, mcp
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 9 hardening rules · 3 OS baselines
V5.3.2V6.2.3V6.4.4V10.4.16
Mitigating Controls (NIST 800-53 r5) AI
Directly mandates unique identification and authentication of users before access to functions requiring identity.
Extends the same authentication requirement to non-organizational users accessing critical functionality.
Requires authentication of services before they can invoke or expose critical functions.
Explicitly identifies and limits actions permitted without authentication, preventing critical functions from being exposed.
Enforces the intended directory access authorizations that path traversal would otherwise bypass.
Information flow enforcement directly requires validating the source of data before allowing transmission or receipt.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Directly requires authentication of users/services/hardware, which eliminates missing authentication for critical functions.
Verifying identity assertions enforces origin validation for conveyed claims.
Documenting authorized flows supports origin validation by defining expected sources.
Managing identities and credentials is a prerequisite for authentication but does not itself enforce it on critical functions.
Defining and enforcing authorizations assumes prior authentication and therefore only partially mitigates the absence of authentication.
Protecting networks from unauthorized access can be undermined by missing authentication but does not address the root authentication gap.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
The control explicitly calls for authentication before any critical function is reached, eliminating the possibility of bypassing authentication for high-value operations.
Security testing in development catches path traversal via static/dynamic analysis.
Mandating authentication requirements for critical functions at the requirements-gathering stage ensures that essential operations are not left unprotected by missing login or verification mechanisms.
Network security controls enforce origin validation at network boundaries.
Mandating authentication for network services and critical functions stops attackers from invoking sensitive operations without credentials, closing gaps where authentication is absent for important capabilities.
Network segregation reduces exposure but does not directly validate origins.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (4 rules)
- V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-346
- V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-346
- V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-306, CWE-346
RHEL 7 (2 rules)
- V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-306
- V-237635 The Red Hat Enterprise Linux operating system must require re-authentication when using the "sudo" command. prevents CWE-306
RHEL 8 (2 rules)
- V-230492 RHEL 8 must not have the rsh-server package installed. prevents CWE-306
- V-237643 RHEL 8 must require re-authentication when using the "sudo" command. prevents CWE-306