CVE-2026-33682: Streamlit on Windows has Unauthenticated SSRF Vulnerability (NTLM Credential Exposure)

Severity: medium (CVSS 4.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-26 · updated 2026-06-17
Weakness: CWE-918

Description

Streamlit is a data oriented application development framework for python. Streamlit Open Source versions prior to 1.54.0 running on Windows hosts have an unauthenticated Server-Side Request Forgery (SSRF) vulnerability. The vulnerability arises from improper validation of attacker-supplied filesystem paths. In certain code paths, including within the `ComponentRequestHandler`, filesystem paths are resolved using `os.path.realpath()` or `Path.resolve()` before sufficient validation occurs. On Windows systems, supplying a malicious UNC path (e.g., `\\attacker-controlled-host\share`) can cause the Streamlit server to initiate outbound SMB connections over port 445. When Windows attempts to authenticate to the remote SMB server, NTLMv2 challenge-response credentials of the Windows user running the Streamlit process may be transmitted. This behavior may allow an attacker to perform NTLM relay attacks against other internal services and/or identify internally reachable SMB hosts via timing analysis. The vulnerability has been fixed in Streamlit Open Source version 1.54.0.

Affected products

streamlit: before 1.54.0 — fixed in 1.54.0

How to fix

Upgrade to a fixed version: streamlit 1.54.0. Check the vendor advisory for mitigations.

References

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