CVE-2026-48710

Published May 26, 2026

Last updated a day ago

CVSS medium 6.5

Port (443)

Overview

Description: 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.
Source: security-advisories@github.com
NVD status: Analyzed
Products: starlette

Risk scores

CVSS 3.1

Type: Primary
Base score: 6.5
Impact score: 2.5
Exploitability score: 3.9
Vector string: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Severity: MEDIUM

Weaknesses

security-advisories@github.com: CWE-444

Hype score: Not currently trending

Configurations

[
  {
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:encode:starlette:*:*:*:*:*:python:*:*",
            "matchCriteriaId": "4C7C6045-86A6-4FAC-AE15-B12438E9D1B4",
            "versionEndExcluding": "1.0.1",
            "versionStartIncluding": "0.8.3",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ]
  }
]

References

Sources include official advisories and independent security research.

Overview

Risk scores

CVSS 3.1

Weaknesses

Social media

Configurations

Related CVEs

References