CVE-2026-48710
published 2026-05-26CVE-2026-48710: 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…
PriorityP348medium6.5CVSS 3.1
AVNACLPRNUINSUCLILAN
EXPLOIT
EPSS
1.44%
70.1th percentile
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.
Affected
73 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| ansible-automation-platform-25 | lightspeed-chatbot-rhel8 | — | — |
| ansible-automation-platform-26 | lightspeed-chatbot-rhel9 | — | — |
| encode | starlette | >= 0 < 1.0.1 | 1.0.1 |
| encode | starlette | >= 0.8.3 < 1.0.1 | 1.0.1 |
| exploit-intelligence-tech-preview | vulnerability-analysis-rhel9 | — | — |
| kludex | starlette | < 1.0.1 | 1.0.1 |
| mta | mta-solution-server-rhel9 | — | — |
| openshift-lightspeed | lightspeed-ocp-rag-rhel9 | — | — |
| openshift-lightspeed | lightspeed-service-api-rhel9 | — | — |
| rhaii | vllm-cpu-rhel9 | — | — |
| rhaii | vllm-cuda-rhel9 | — | — |
| rhaii | vllm-gaudi-rhel9 | — | — |
| rhaii | vllm-neuron-rhel9 | — | — |
| rhaii | vllm-rocm-rhel9 | — | — |
| rhaii | vllm-spyre-rhel9 | — | — |
| rhaii | vllm-tpu-rhel9 | — | — |
| rhaiis | vllm-cpu-rhel9 | — | — |
| rhaiis | vllm-cuda-rhel9 | — | — |
| rhaiis | vllm-neuron-rhel9 | — | — |
| rhaiis | vllm-rocm-rhel9 | — | — |
| rhaiis | vllm-spyre-rhel9 | — | — |
| rhaiis | vllm-tpu-rhel9 | — | — |
| rhelai3 | bootc-aws-cuda-rhel9 | — | — |
| rhelai3 | bootc-azure-cuda-rhel9 | — | — |
| rhelai3 | bootc-azure-rocm-rhel9 | — | — |
CVSS provenance
nvdv3.16.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
vendor_redhat6.5MEDIUM
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GHSA
Starlette has missing Host header validation that poisons request.url.path, bypassing path-based security checks
ghsa·2026-06-04
CVE-2026-48710 [MEDIUM] CWE-444 Starlette has missing Host header validation that poisons request.url.path, bypassing path-based security checks
Starlette has missing Host header validation that poisons request.url.path, bypassing path-based security checks
### Summary
In affected versions, 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.
### Details
When a client requests `http://example.com/foo`, it sends:
```http
GET /foo HTTP/1.1
Host: example.com
```
Affected versions reconstructed the URL by concatenating `http://{host}{path
VulDB
Kludex starlette up to 1.0.0 Request Header request smuggling (GHSA-86qp-5c8j-p5mr / Nessus ID 316593)
vuldb·2026-05-29·CVSS 6.5
CVE-2026-48710 [MEDIUM] Kludex starlette up to 1.0.0 Request Header request smuggling (GHSA-86qp-5c8j-p5mr / Nessus ID 316593)
A vulnerability was found in Kludex starlette up to 1.0.0. It has been rated as critical. This impacts an unknown function of the component Request Header Handler. This manipulation causes http request smuggling.
The identification of this vulnerability is CVE-2026-48710. It is possible to initiate the attack remotely. There is no exploit available.
Upgrading the affected component is advised.
Red Hat
starlette: Starlette: Security restriction bypass via malformed HTTP Host header
vendor_redhat·2026-05-26·CVSS 6.5
CVE-2026-48710 [MEDIUM] CWE-1289 starlette: Starlette: Security restriction bypass via malformed HTTP Host header
starlette: Starlette: Security restriction bypass via malformed HTTP Host header
A flaw was found in Starlette, a lightweight ASGI (Asynchronous Server Gateway Interface) framework. A remote attacker could exploit this vulnerability by sending a specially crafted HTTP `Host` request header. This malformed header could cause the `request.url` to be incorrectly reconstructed, leading to a discrepancy with the actual requested path. Consequently, security restrictions enforced by middleware and endpoints that rely on `request.url` for validation could be bypassed, potentially allowing unauthorized access or actions.
Package: exploit-intelligence-tech-preview/vulnerability-analysis-rhel9 (Exploit Intelligence) - Affected
Package: mta/mta-solution-server-rhel9 (Migration Toolkit for Applicat
No detection rules found.
Nuclei
Starlette - Improper Validation of Unsafe Equivalence in Input
nuclei·CVSS 6.5
CVE-2026-48710 [MEDIUM] Starlette - Improper Validation of Unsafe Equivalence in Input
Starlette - Improper Validation of Unsafe Equivalence in Input
A flaw was found in Starlette, a lightweight ASGI (Asynchronous Server Gateway Interface) framework. A remote attacker could exploit this vulnerability by sending a specially crafted HTTP Host request header. This malformed header could cause the request.url to be incorrectly reconstructed, leading to a discrepancy with the actual requested path. Consequently, security restrictions enforced by middleware and endpoints that rely on request.url for validation could be bypassed, potentially allowing unauthorized access or actions.
Template:
id: CVE-2026-48710
info:
name: Starlette - Improper Validation of Unsafe Equivalence in Input
author: ritikchaddha
severity: critical
description: |
A flaw was found in Starlette, a lightwe
Nuclei
LiteLLM - Command Injection
nuclei·CVSS 8.7
CVE-2026-42271 [HIGH] LiteLLM - Command Injection
LiteLLM - Command Injection
A critical unauthenticated remote code execution vulnerability exists in LiteLLM due to improper input handling in the MCP stdio test endpoint. An attacker can send a specially crafted request to the `/mcp-rest/test/connection` endpoint with controlled parameters, resulting in arbitrary command execution on the server. When combined with an authentication bypass technique—such as the Starlette BadHost flaw (CVE-2026-48710)—an unauthenticated attacker can exploit the chain to execute commands as the server process. Exploitation allows an attacker to spawn processes with the privileges of the LiteLLM server, potentially leading to complete compromise of the host.
Template:
id: CVE-2026-42271
info:
name: LiteLLM - Command Injection
author: ritikchaddha
severity
Hackernews
LiteLLM Flaw CVE-2026-42271 Exploited in the Wild, Chains to Unauthenticated RCE
blogs_hackernews·2026-06-09·CVSS 8.8
CVE-2026-42271 [HIGH] LiteLLM Flaw CVE-2026-42271 Exploited in the Wild, Chains to Unauthenticated RCE
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## LiteLLM Flaw CVE-2026-42271 Exploited in the Wild, Chains to Unauthenticated RCE
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Monday added a high-severity flaw impacting BerriAI LiteLLM to its Known Exploited Vulnerabilities ( KEV ) catalog, citing evidence of active exploitation.
The vulnerability, tracked as CVE-2026-42271 (CVSS score: 8.7), is a command injection vulnerability that could allow any authenticated user to run arbitrary commands on the host.
It affects the following version of the LiteLLM Python package -
>= 1.74.2
< 1.83.7
"Two endpoints used to preview an MCP server before saving
Bugzilla
CVE-2026-48710 starlette: Starlette: Security restriction bypass via malformed HTTP Host header
bugzilla·2026-05-26·CVSS 6.5
CVE-2026-48710 [MEDIUM] CVE-2026-48710 starlette: Starlette: Security restriction bypass via malformed HTTP Host header
CVE-2026-48710 starlette: Starlette: Security restriction bypass via malformed HTTP Host header
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 constr
https://badhost.orghttps://github.com/Kludex/starlette/commit/764dab0dcfb9033d75442d7a359645c9f94648c6https://github.com/Kludex/starlette/security/advisories/GHSA-86qp-5c8j-p5mrhttps://github.com/pypa/advisory-database/tree/main/vulns/starlette/PYSEC-2026-161.yamlhttps://ostif.org/disclosing-the-badhost-vulnerability-in-starlettehttps://www.secwest.net/starlettehttps://www.x41-dsec.de/lab/advisories/x41-2026-002-starlettehttps://access.redhat.com/errata/RHSA-2026:22992https://access.redhat.com/errata/RHSA-2026:22993https://access.redhat.com/errata/RHSA-2026:23346https://access.redhat.com/errata/RHSA-2026:24866https://access.redhat.com/errata/RHSA-2026:26226https://access.redhat.com/errata/RHSA-2026:30088https://access.redhat.com/errata/RHSA-2026:30089https://access.redhat.com/errata/RHSA-2026:34456https://access.redhat.com/errata/RHSA-2026:34526https://access.redhat.com/errata/RHSA-2026:34532https://access.redhat.com/errata/RHSA-2026:37275https://access.redhat.com/security/cve/CVE-2026-48710https://bugzilla.redhat.com/show_bug.cgi?id=2481742https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48710.json
2026-05-26
Published