CVE-2026-54282

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 3.7 LOW

3.7^/10

CVSS v3 : LOW

Vector :

Exploitability : 2.2 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/Kludex/starlette/security/advisories/GHSA-jp82-jpqv-5vv3	Mitigation Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:encode:starlette:*:*:*:*:*:python:*:*

History

25 Oct 2026, 23:10

Type	Values Removed	Values Added
Summary		(es) Starlette es un framework/conjunto de herramientas ASGI ligero. Antes de la versión 1.3.0, la ruta de solicitud HTTP no se valida antes de ser utilizada para reconstruir request.url. Debido a que request.url se reconstruye concatenando {scheme}://{host}{path} y volviendo a analizar el resultado, una ruta que no comienza con / (por ejemplo, @google.com) mueve el límite de autoridad durante el reanálisis, por lo que request.url.hostname y request.url.netloc pasan a estar controlados por el atacante. El código que lee request.url.hostname (en lugar del encabezado Host o el ámbito) puede, por lo tanto, ser engañado para confiar en un host proporcionado por el atacante. Esta vulnerabilidad se corrige en la versión 1.3.0.

Information

Published : 2026-06-22 18:16

Updated : 2026-10-25 23:10

NVD link : CVE-2026-54282

Mitre link : CVE-2026-54282

CVE.ORG link : CVE-2026-54282

JSON object : View

Products Affected

encode

starlette

CWE

CWE-706

Use of Incorrectly-Resolved Name or Reference

{"id": "CVE-2026-54282", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-54282", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-06-22T17:26:39.551031Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 3.7, "attackVector": "NETWORK", "baseSeverity": "LOW", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 1.4, "exploitabilityScore": 2.2}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 1.4, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "Kludex", "product": "starlette", "versions": [{"status": "affected", "version": "< 1.3.0"}]}]}], "published": "2026-06-22T18:16:46.807", "references": [{"url": "https://github.com/Kludex/starlette/security/advisories/GHSA-jp82-jpqv-5vv3", "tags": ["Mitigation", "Vendor Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-706"}]}], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "Starlette es un framework/conjunto de herramientas ASGI ligero. Antes de la versi\u00f3n 1.3.0, la ruta de solicitud HTTP no se valida antes de ser utilizada para reconstruir request.url. Debido a que request.url se reconstruye concatenando {scheme}://{host}{path} y volviendo a analizar el resultado, una ruta que no comienza con / (por ejemplo, @google.com) mueve el l\u00edmite de autoridad durante el rean\u00e1lisis, por lo que request.url.hostname y request.url.netloc pasan a estar controlados por el atacante. El c\u00f3digo que lee request.url.hostname (en lugar del encabezado Host o el \u00e1mbito) puede, por lo tanto, ser enga\u00f1ado para confiar en un host proporcionado por el atacante. Esta vulnerabilidad se corrige en la versi\u00f3n 1.3.0."}], "lastModified": "2026-10-25T23:10:00.167", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:encode:starlette:*:*:*:*:*:python:*:*", "vulnerable": true, "matchCriteriaId": "8E74BF7B-56BA-47FC-9912-59DB97B61460", "versionEndExcluding": "1.3.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}