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CVE-2026-48710

CVE-2026-48710 · Starlette has missing Host header validation that poisons request.url.path, bypassing path-based security checks

This page contains facts from public vulnerability sources. Check the original advisory before updating.

This page shows selected source facts. See the linked advisories for the complete description and affected versions.

Starlette is a lightweight ASGI framework/toolkit. Prior to version 1.0.1, the HTTP `Host` request header was not validated before being used to reconstruct `request.url`. Because the routing algorithm relies on the raw HTTP path while `request.url` is rebuilt from the `Host` header, a malformed header could make `request.url.path` differ from the path that was actually requested. Middleware and endpoints that apply security restrictions based on `request.url` (rather than the raw `scope` path) could therefore be bypassed. Users should upgrade to a version greater than or equal to version 1.0.1, which validates the `Host` header against the grammar of RFC 9112 §3.2 / RFC 3986 §3.2.2 when constructing `request.url` and falls back to `scope["server"]` for malformed values.

CVSS 6.5 · Medium · EPSS 70.3% · In KEV · Public exploit · Fix available

Published
Updated

Stack: system · python

Affected products and versions

  • starlette

    Versions
    • < 1.0.1: Affected

    No fix published

  • starlette Debian:12

    Versions
    • 0.26.1-1
    Affected ranges
    • ECOSYSTEM: < 0.26.1-1+deb12u1

    Update to 0.26.1-1+deb12u1

  • starlette Debian:13

    Versions
    • 0.46.1-3
    • 0.46.1-3+deb13u1
    Affected ranges
    • ECOSYSTEM: < 0.46.1-3+deb13u2

    Update to 0.46.1-3+deb13u2

  • starlette Debian:14

    Versions
    • 0.46.1-3
    • 0.50.0-1
    • 1.0.0-1
    Affected ranges
    • ECOSYSTEM: < 1.1.0-1

    Update to 1.1.0-1

  • starlette PyPI

    Versions
    • 0.1.0
    • 0.1.1
    • 0.1.10
    • 0.1.11
    • 0.1.12
    • 0.1.13
    • 0.1.14
    • 0.1.15
    • 0.1.16
    • 0.1.17
    • 0.1.2
    • 0.1.3
    • 0.1.4
    • 0.1.5
    • 0.1.6
    • 0.1.7
    • 0.1.8
    • 0.1.9
    • 0.10.0
    • 0.10.1
    • 0.10.2
    • 0.10.3
    • 0.10.4
    • 0.10.5
    • 0.10.6
    • 0.10.7
    • 0.11.0
    • 0.11.1
    • 0.11.2
    • 0.11.3
    • 0.11.4
    • 0.12.0
    • 0.12.0b1
    • 0.12.0b2
    • 0.12.0b3
    • 0.12.1
    • 0.12.10
    • 0.12.11
    • 0.12.12
    • 0.12.13
    • 0.12.2
    • 0.12.3
    • 0.12.4
    • 0.12.5
    • 0.12.6
    • 0.12.7
    • 0.12.8
    • 0.12.9
    • 0.13.0
    • 0.13.1
    • 0.13.2
    • 0.13.3
    • 0.13.4
    • 0.13.5
    • 0.13.6
    • 0.13.7
    • 0.13.8
    • 0.14.0
    • 0.14.1
    • 0.14.2
    • 0.15.0
    • 0.16.0
    • 0.17.0
    • 0.17.1
    • 0.18.0
    • 0.19.0
    • 0.19.1
    • 0.2.0
    • 0.2.1
    • 0.2.2
    • 0.2.3
    • 0.20.0
    • 0.20.1
    • 0.20.2
    • 0.20.3
    • 0.20.4
    • 0.21.0
    • 0.22.0
    • 0.23.0
    • 0.23.1
    • 0.24.0
    • 0.25.0
    • 0.26.0
    • 0.26.0.post1
    • 0.26.1
    • 0.27.0
    • 0.28.0
    • 0.29.0
    • 0.3.0
    • 0.3.1
    • 0.3.2
    • 0.3.3
    • 0.3.4
    • 0.3.5
    • 0.3.6
    • 0.3.7
    • 0.30.0
    • 0.31.0
    • 0.31.1
    • 0.32.0
    • 0.32.0.post1
    • 0.33.0
    • 0.34.0
    • 0.35.0
    • 0.35.1
    • 0.36.0
    • 0.36.1
    • 0.36.2
    • 0.36.3
    • 0.37.0
    • 0.37.1
    • 0.37.2
    • 0.38.0
    • 0.38.1
    • 0.38.2
    • 0.38.3
    • 0.38.4
    • 0.38.5
    • 0.38.6
    • 0.39.0
    • 0.39.1
    • 0.39.2
    • 0.4.0
    • 0.4.1
    • 0.4.2
    • 0.40.0
    • 0.41.0
    • 0.41.1
    • 0.41.2
    • 0.41.3
    • 0.42.0
    • 0.43.0
    • 0.44.0
    • 0.45.0
    • 0.45.1
    • 0.45.2
    • 0.45.3
    • 0.46.0
    • 0.46.1
    • 0.46.2
    • 0.47.0
    • 0.47.1
    • 0.47.2
    • 0.47.3
    • 0.48.0
    • 0.49.0
    • 0.49.1
    • 0.49.2
    • 0.49.3
    • 0.5.0
    • 0.5.1
    • 0.5.2
    • 0.5.3
    • 0.5.4
    • 0.5.5
    • 0.50.0
    • 0.51.0
    • 0.52.0
    • 0.52.1
    • 0.6.0
    • 0.6.1
    • 0.6.2
    • 0.6.3
    • 0.7.0
    • 0.7.1
    • 0.7.2
    • 0.7.3
    • 0.7.4
    • 0.8.0
    • 0.8.1
    • 0.8.2
    • 0.8.3
    • 0.8.4
    • 0.8.5
    • 0.8.6
    • 0.8.7
    • 0.8.8
    • 0.9.0
    • 0.9.1
    • 0.9.10
    • 0.9.11
    • 0.9.2
    • 0.9.3
    • 0.9.4
    • 0.9.5
    • 0.9.6
    • 0.9.7
    • 0.9.8
    • 0.9.9
    • 1.0.0
    • 1.0.0rc1
    Affected ranges
    • ECOSYSTEM: < 1.0.1

    Update to 1.0.1

  • starlette Ubuntu:22.04:LTS

    Versions
    • 0.14.1-1
    • 0.16.0-1
    • 0.18.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • starlette Ubuntu:24.04:LTS

    Versions
    • 0.30.0-1
    • 0.31.1-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • starlette Ubuntu:25.10

    Versions
    • 0.46.1-2
    • 0.46.1-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • starlette Ubuntu:26.10

    Versions
    • 0.50.0-1
    • 1.1.0-1
    • 1.3.1-1
    • 1.7.0-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • starlette Ubuntu:26.04:LTS

    Versions
    • 0.46.1-3
    • 0.50.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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