Detections
Analytics
CVE-2026-48818
high
Description
Starlette is a lightweight ASGI framework/toolkit. In versions 1.0.1 and earlier, StaticFiles on Windows is vulnerable to SSRF. An UNC path such as \\attacker.com\share can cause os.path.realpath to initiate an outbound SMB connection before the path is rejected, exposing the service account’s NTLMv2 credentials for offline cracking or relay even though the HTTP response is only a 404. The issue affects default follow_symlink=False deployments, including frameworks built on Starlette such as FastAPI; POSIX systems and follow_symlink=True are unaffected. The issue is fixed in 1.1.0.
References
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48818.json
https://github.com/Kludex/starlette/security/advisories/GHSA-wqp7-x3pw-xc5r
https://github.com/Kludex/starlette/releases/tag/1.1.0
https://github.com/Kludex/starlette/pull/3287
https://github.com/Kludex/starlette/commit/fd53168a7767b6b55ba5af787fd88f49e33cabc5
https://bugzilla.redhat.com/show_bug.cgi?id=2490020
https://access.redhat.com/security/cve/CVE-2026-48818
https://access.redhat.com/errata/RHSA-2026:30089