CVE-2026-49138 Nanobot < 0.2.1 SSRF via web_fetch Tool Redirect Following
Remote attackers can exploit redirect handling in the web_fetch tool to access internal network hosts, requiring an upgrade to Nanobot.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-49138?
CVE-2026-49138 is a medium-severity server-side request forgery vulnerability in HKUDS nanobot, published on 1 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Weakness: CWE-918
Which versions are affected by CVE-2026-49138?
3 open source packages ship an affected version, including nanobot-ai.
| Package | Affected | Fixed in |
|---|---|---|
nanobot-ai PyPI | All versions | 0.2.1 |
nanobot-ai PyPI | All versions | 0.2.1 |
nanobot-ai PyPI | All versions | 0.2.1 |
How do I fix CVE-2026-49138?
Upgrade nanobot-ai to 0.2.1 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-49138 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-49138 exists.
Sources
Also known as GHSA-434r-7c99-hwf3, PYSEC-2026-3580.