mcp-searxng

### Summary mcp-searxng version 1.11.0 exposes SearXNG Basic Authentication credentials embedded in the `SEARXNG_URL` environment variable. When the server starts in STDIO mode and an MCP client connects, the complete `SEARXNG_URL`, including its username and password, is sent to the client through an MCP `notifications/message` logging notification. Additionally, when URL validation fails, the complete credential-bearing URL is included in the configuration error. This error is logged through MCP and returned to the client as a JSON-RPC error response. For example, a value such as: ```te

Ref: https://github.com/ihor-sokoliuk/mcp-searxng/issues/87#issuecomment-4645453694 ### Summary The web_url_read tool fetches a caller-supplied URL server-side and converts it to markdown. An SSRF guard (assertUrlAllowed, which blocks private/loopback/metadata addresses) exists but runs only when MCP_HTTP_HARDEN=true, which is off by default. So in the default configuration there is no internal-address filtering, and an attacker who can influence the URL can make the server fetch internal services and cloud metadata and return their content. Confirmed on 1.1.0 (default config): web_url_read

CVE: CVE-2026-54688

## Summary `mcp-searxng` has a hardened-mode URL-reading feature intended to prevent `web_url_read` from reaching private or internal network resources. PR #79 appears to address one SSRF class: hostnames that resolve to private or internal addresses under hardened mode. I tested PR #79 locally and confirmed that it blocks the DNS-resolves-to-loopback case. However, several other hardened-mode SSRF bypasses still appear to remain: 1. Redirects from an allowed first-hop URL to a loopback/internal URL are followed without re-validating the redirect target. 2. `0.0.0.0` is not treated as an i

CVE: CVE-2026-54689

## DNS-resolved Private Hostname SSRF in `web_url_read` ### Summary The `web_url_read` MCP tool in `mcp-searxng` is vulnerable to Server-Side Request Forgery (SSRF) via DNS rebinding bypass. The `assertUrlAllowed()` function at `src/url-reader.ts:85-93` validates only the syntactic hostname string against a private IP/hostname blocklist without performing DNS resolution. An attacker who controls a domain that resolves to a private or loopback IP address (e.g., via a wildcard DNS service like `nip.io`, or a custom DNS entry) can bypass the security check and cause the MCP server to read arbit

CVE: CVE-2026-58485

## Unbounded Response Body Read Bypasses URL Size Limit in `web_url_read` ### Summary The `web_url_read` MCP tool in mcp-searxng enforces its 5 MiB response-size limit exclusively by inspecting the `Content-Length` header of a preliminary HEAD request. When a server omits `Content-Length` — a standard HTTP practice — `checkContentLength()` returns `null`, the guard condition short-circuits to `false`, and `response.text()` loads the entire response body into memory without any byte cap. An unauthenticated attacker who controls or can redirect to an HTTP endpoint can force the server process

CVE: CVE-2026-58483