# Nanobot contains a server-side request forgery vulnerability in the web_fetch tool

Advisory record · `GHSA-434r-7c99-hwf3`

- **Identifiers:** `GHSA-434r-7c99-hwf3` · `CVE-2026-49138` · `PYSEC-2026-3580`
- **State:** Confirmed
- **Severity:** CVSS 5.3 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-918](https://cwe.mitre.org/data/definitions/918.html)
- **Tags:** [Server-side request forgery (SSRF)](https://agentprime.io/advisories/tag/ssrf.md)
- **Published:** 1 Jun 2026
- **Updated:** 4 Aug 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 1 Jun 2026, 21:30 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `nanobot-ai` (PyPI): affected `<0.2.1`; fixed in `0.2.1`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Nanobot versions before 0.2.1 are vulnerable to server-side request forgery through the web_fetch tool. A remote attacker who can supply a URL to that tool can use a redirect to a loopback or private address to make the server send requests to internal hosts, because redirects are followed before the final address is checked. Upgrade to nanobot-ai version 0.2.1 or later, which is the fixed version listed.

Written 5 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 5.3 Medium, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:L/SI:N/SA:N`, from CNA (VulnCheck)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0036, the 29th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 1 Jun 2026, 19:41 UTC: [Confirmed by the CVE List](https://www.cve.org/CVERecord?id=CVE-2026-49138)
- 31 Oct 2026, 14:40 UTC: First seen by agentprime
- 31 Oct 2026, 14:40 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-434r-7c99-hwf3)

## Sources

- [GitHub Advisory Database: GHSA-434r-7c99-hwf3](https://github.com/advisories/GHSA-434r-7c99-hwf3)
- [OSV: GHSA-434r-7c99-hwf3](https://osv.dev/vulnerability/GHSA-434r-7c99-hwf3)
- <https://nvd.nist.gov/vuln/detail/CVE-2026-49138>
- <https://github.com/HKUDS/nanobot/pull/3928>
- <https://github.com/HKUDS/nanobot/commit/545294c62c0947da40eb5b65288aaf02b5fdf632>
- <https://github.com/HKUDS/nanobot>
- <https://github.com/HKUDS/nanobot/releases/tag/v0.2.1>
- <https://www.vulncheck.com/advisories/nanobot-ssrf-via-web-fetch-tool-redirect-following>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-434r-7c99-hwf3>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-434r-7c99-hwf3/>. Everything for agents: <https://agentprime.io/llms.txt>.