CVE-2026-42260

HIGH

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

Title source: cna
STIX 2.1

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.

References (1)

Core 1
Core References

Scores

CVSS v3 8.2
EPSS 0.0004
EPSS Percentile 11.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-918
Status published
Products (2)
Aas-ee/open-webSearch < 2.1.7
npm/open-websearch 0 - 2.1.7npm
Published May 12, 2026
Tracked Since May 12, 2026