CVE-2026-54282: CWE-706: Use of Incorrectly-Resolved Name or Reference in Kludex starlette
Starlette is a lightweight ASGI framework/toolkit. Prior to 1.3.0, the HTTP request path is not validated before being used to reconstruct request.url. Because request.url is rebuilt by concatenating {scheme}://{host}{path} and re-parsing the result, a path that does not begin with / (for example @google.com) moves the authority boundary during re-parsing, so request.url.hostname and request.url.netloc become attacker-controlled. Code that reads request.url.hostname (rather than the Host header or scope) can therefore be misled into trusting an attacker-supplied host. This vulnerability is fixed in 1.3.0.
AI Analysis
Technical Summary
In Starlette, a lightweight ASGI framework, versions before 1.3.0 do not validate the HTTP request path before rebuilding request.url by concatenating scheme, host, and path and then re-parsing. If the path does not start with a slash (e.g., '@google.com'), the re-parsing shifts the authority boundary, making request.url.hostname and request.url.netloc attacker-controlled. This can cause downstream code that relies on request.url.hostname for host validation to trust attacker-supplied values. The vulnerability is identified as CWE-706 (Use of Incorrectly-Resolved Name or Reference) and is resolved in Starlette 1.3.0.
Potential Impact
The vulnerability allows an attacker to manipulate the hostname and network location components of the reconstructed request URL by supplying a crafted path. This can mislead application logic that trusts request.url.hostname for host validation, potentially causing incorrect authorization or routing decisions. The CVSS score is 3.7 (low severity), indicating limited impact with no confidentiality or availability effects, but some integrity impact due to misleading host information.
Mitigation Recommendations
Upgrade Starlette to version 1.3.0 or later, where this issue is fixed. There is no official patch link provided, but the vendor has resolved the vulnerability in 1.3.0. Until upgraded, avoid relying on request.url.hostname for security decisions; instead, use the Host header or ASGI scope information for host validation.
CVE-2026-54282: CWE-706: Use of Incorrectly-Resolved Name or Reference in Kludex starlette
Description
Starlette is a lightweight ASGI framework/toolkit. Prior to 1.3.0, the HTTP request path is not validated before being used to reconstruct request.url. Because request.url is rebuilt by concatenating {scheme}://{host}{path} and re-parsing the result, a path that does not begin with / (for example @google.com) moves the authority boundary during re-parsing, so request.url.hostname and request.url.netloc become attacker-controlled. Code that reads request.url.hostname (rather than the Host header or scope) can therefore be misled into trusting an attacker-supplied host. This vulnerability is fixed in 1.3.0.
CVSS v3.1
Score 3.7low
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
In Starlette, a lightweight ASGI framework, versions before 1.3.0 do not validate the HTTP request path before rebuilding request.url by concatenating scheme, host, and path and then re-parsing. If the path does not start with a slash (e.g., '@google.com'), the re-parsing shifts the authority boundary, making request.url.hostname and request.url.netloc attacker-controlled. This can cause downstream code that relies on request.url.hostname for host validation to trust attacker-supplied values. The vulnerability is identified as CWE-706 (Use of Incorrectly-Resolved Name or Reference) and is resolved in Starlette 1.3.0.
Potential Impact
The vulnerability allows an attacker to manipulate the hostname and network location components of the reconstructed request URL by supplying a crafted path. This can mislead application logic that trusts request.url.hostname for host validation, potentially causing incorrect authorization or routing decisions. The CVSS score is 3.7 (low severity), indicating limited impact with no confidentiality or availability effects, but some integrity impact due to misleading host information.
Mitigation Recommendations
Upgrade Starlette to version 1.3.0 or later, where this issue is fixed. There is no official patch link provided, but the vendor has resolved the vulnerability in 1.3.0. Until upgraded, avoid relying on request.url.hostname for security decisions; instead, use the Host header or ASGI scope information for host validation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-12T17:46:37.292Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a39735ceed863c81e39629b
Added to database: 06/22/2026, 17:39:40 UTC
Last enriched: 06/22/2026, 17:55:09 UTC
Last updated: 06/22/2026, 20:05:34 UTC
Views: 4
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