CVE-2026-48764 - TypeBot SSRF Vulnerability Exploited via DNS Rebinding

CVE-2026-48764 - TypeBot SSRF Vulnerability Exploited via DNS Rebinding

CVE-2026-48764 impacts TypeBot, a chatbot builder tool. In versions prior to 3.17.2, a significant SSRF vulnerability exists. The validation process is implemented by resolving a hostname once and checking whether the resolved IP belongs to a forbidden range, which then allows for DNS rebinding bypass. 🚨

The root cause of this vulnerability is identified as a time-of-check to time-of-use (TOCTOU) gap in the SSRF guard. Specifically, the validator initially resolves the hostname and approves it. However, the later request path performs a fresh resolution and connects to whatever IP the hostname maps to at that moment. The actual outbound request is subsequently performed later using the original hostname, crucially without pinning the validated IP to the network connection.

An attacker who can supply a URL to a public bot that performs a server-side HTTP Request block or server-side script fetch can exploit this by using DNS rebinding. This allows them to effectively pass the initial validation and still force the server to connect to a private or metadata address during the real request. Consequently, this attack enables server-side access to private network services, cloud metadata endpoints, and other internal HTTP targets that the validator was intended to block. The exact downstream impact depends on the specific reachable internal services. Concrete consequences stemming from this issue include metadata disclosure, access to internal admin panels, credential theft from metadata services, and further compromise through internal-only HTTP interfaces. 🔒

It is confirmed that this issue has been fixed in version 3.17.2.

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