Vulnerability · Published Jun 1, 2026 · Assigned by VulnCheck

CVE-2026-49138Nanobot < 0.2.1 SSRF via web_fetch Tool Redirect Following

Medium 5.0

In plain English

A medium-severity server-side request forgery in nanobot from HKUDS. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.0Medium

Exploit odds (30 days)0.4%top 70.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Nanobot prior to version 0.2.1 contains a server-side request forgery vulnerability in the web_fetch tool that allows remote attackers to reach internal or private network hosts by supplying a URL that redirects to a loopback or private address via a 3xx Location header. Attackers can exploit the automatic HTTP redirect following behavior in the httpx library to bypass initial URL validation and cause the runtime to send outbound requests to internal hosts before final resolved URL validation is applied.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	nanobot-ai	0.2.1	GHSA-434r-7c99-hwf3
PyPI	nanobot-ai	0.2.1	PYSEC-2026-3580

Affected products (as reported)

Vendor	Product	Versions
HKUDS	nanobot	0 – before 0.2.1

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

References

https://github.com/HKUDS/nanobot/releases/tag/v0.2.1 release-notes
https://github.com/HKUDS/nanobot/pull/3928 issue-tracking
https://github.com/HKUDS/nanobot/commit/545294c62c0947da40eb5b65288aaf02b5fdf632 patch
https://www.vulncheck.com/advisories/nanobot-ssrf-via-web-fetch-tool-redirect-following third-party-advisory