Server-Side Request Forgery (SSRF) in starlette - CVE-2026-48818
Published: May 25, 2026
Vulnerability identifier: #VU132267
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-48818
CWE-ID: CWE-918
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to server-side request forgery (SSRF) in StaticFiles.lookup_path() when processing a UNC path on Windows. A remote attacker can send a specially crafted request containing a UNC path to disclose sensitive information.
Only Windows systems using the default configuration with follow_symlink set to false are affected. The issue can leak the service account's NTLMv2 credentials to an attacker-controlled SMB host.
Affected software
starlette
How to mitigate CVE-2026-48818
Install security update from vendor's website.
starlette - update to 1.1.0