Vulnerability · Published Jun 1, 2026 · Assigned by VulnCheck

CVE-2026-49139Nanobot < 0.2.1 SSRF via Microsoft Teams Channel serviceUrl Poisoning

High 7.0

In plain English

A high-severity server-side request forgery in nanobot from HKUDS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 32% of all known vulnerabilities).

Severity (CVSS 4.0)7.0High

Exploit odds (30 days)0.4%top 67.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Nanobot prior to version 0.2.1 contains a server-side request forgery vulnerability in the Microsoft Teams channel handler that allows remote attackers to exfiltrate Bot Framework bearer tokens by supplying a forged activity with an attacker-controlled serviceUrl value. Attackers can poison the stored conversation reference by sending a crafted inbound activity to the Teams webhook, causing subsequent bot replies to transmit token-bearing Authorization header requests to an attacker-controlled host.

Affected products (as reported)

Vendor	Product	Versions
HKUDS	nanobot	0 – before 0.2.1

Weakness: CWE-918 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:H/SI:H/SA:N

References

https://github.com/HKUDS/nanobot/releases/tag/v0.2.1 release-notes
https://github.com/HKUDS/nanobot/pull/4047 issue-tracking
https://github.com/HKUDS/nanobot/commit/232df45126bcf0f8fccd123d73714f202c8e8612 patch
https://www.vulncheck.com/advisories/nanobot-ssrf-via-microsoft-teams-channel-serviceurl-poisoning third-party-advisory