Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V4 - API and Web Service HTTP request consistency
|
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Alert meAnalysisAIv1 – May 26, 2026
Host header injection in Starlette prior to version 1.0.1 allows unauthenticated remote attackers to cause request.url.path to differ from the actual ASGI scope path used for routing, enabling bypass of middleware and endpoint security controls that rely on request.url rather than the raw scope. Any application enforcing path-based ACLs, authentication gates, or WAF-style filters through request.url is affected, as a crafted Host header can make the URL appear to address a permitted path while the real route differs. This issue carries CVSS 6.5 (AV:N/AC:L/PR:N/UI:N); no public exploit has been identified at time of analysis and it is not listed in CISA KEV.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in pypi
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Severity by source
Sources disagree (Medium–Critical)AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
vuln.today treats the vendor’s rating as authoritative. A higher third-party CVSS (e.g. CISA-ADP) is shown for transparency but does not drive the headline severity.
CVSS VectorNVD
Lifecycle Timeline
1DescriptionNVD
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.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
HTTP request smuggling exploits inconsistencies in how front-end and back-end servers parse HTTP message boundaries.
Directory traversal vulnerability in Starlette versions 0.13.5 and later and prior to 0.27.0 allows a remote unauthentic
There MultipartParser usage in Encode's Starlette python framework before versions 0.25.0 allows an unauthenticated and
Same weakness CWE-444 – HTTP Request/Response Smuggling
View allSame technique Authentication Bypass
View allVendor StatusVendor
SUSE
Severity: Medium| Product | Status |
|---|---|
| SUSE Linux Enterprise Server 16.0 | Fixed |
| SUSE Linux Enterprise Server 16.1 | Fixed |
| SUSE Linux Enterprise Server for SAP applications 16.0 | Fixed |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Fixed |
| openSUSE Leap 16.0 | Fixed |
EUVD-2026-32016
GHSA-86qp-5c8j-p5mr
NVD
CVE.org
CISA KEV
EPSS
Vulnrichment
VulDB
Exploit-DB