CVE-2026-42260 json
Open-WebSearch: SSRF in `fetchWebContent` MCP tool: bracketed IPv6 literals and non-resolving hostname check bypass `isPrivateOrLocalHostname`
published 2026-05-05 6 mo ago modified 2026-10-26 13 d ago also GHSA-v228-72c7-fx8j , EUVD-2026-29478
- cvss
- 8.2
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 17%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- npm open-websearch 2.1.7
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 5 mo ago
Exploit prediction
0.26% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/Aas-ee/open-webSearch/security/advisories/GHSA-v228-72c7-fx8j referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N |
| GitHub | 3.1 | 8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | open-websearch | <2.1.7 |
2.1.7 |
Affected products
- Aas-ee open-webSearch
Classification
References
Sources
- CVE List CVE-2026-42260
- GitHub Advisory GHSA-v228-72c7-fx8j
- NVD CVE-2026-42260
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