Vulnerability · Published May 12, 2026 · Assigned by GitHub_M

CVE-2026-42260Open-WebSearch: SSRF in `fetchWebContent` MCP tool: bracketed IPv6 literals and non-resolving hostname check bypass `isPrivateOrLocalHostname`

High 8.2

In plain English

A high-severity server-side request forgery in open-webSearch from Aas-ee. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 18% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.2High

Exploit odds (30 days)0.3%top 82.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Open-WebSearch is a multi-engine MCP server, CLI, and local daemon for agent web search and content retrieval. Prior to 2.1.7, isPublicHttpUrl / assertPublicHttpUrl in src/utils/urlSafety.ts do not recognize bracketed IPv6 literals and do not resolve DNS, which combine to allow non-blind SSRF with the response body returned to the caller. This vulnerability is fixed in 2.1.7.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	open-websearch	2.1.7	GHSA-v228-72c7-fx8j

Affected products (as reported)

Vendor	Product	Versions
Aas-ee	open-webSearch	< 2.1.7

Weakness: CWE-918 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

References

https://github.com/Aas-ee/open-webSearch/security/advisories/GHSA-v228-72c7-fx8j x_refsource_CONFIRM