Starlette has missing Host header validation that poisons request.url.path, bypassing path-based security checks
Summary
| CVE | CVE-2026-48710 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-26 22:16:44 UTC |
| Updated | 2026-06-16 13:16:35 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 6.5 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS: 0.010020000 probability, percentile 0.583460000 (date 2026-06-18)
Problem Types: CWE-444 | CWE-1289 | CWE-444 CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') | CWE-1289 CWE-1289
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
| 3.1 | ADP | CVSS | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
| 3.1 | [email protected] | Secondary | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
| 3.1 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | Secondary | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
| 3.1 | CNA | DECLARED | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD Known Affected Configurations (CPE 2.3)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Kludex | Starlette | affected < 1.0.1 | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ansible Automation Platform-2 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ansible Automation Platform-2 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ansible Automation Platform-2 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Mta-8 | Not specified | Not specified |
| ADP | Red Hat | Exploit-intelligence | Not specified | Not specified |
| ADP | Red Hat | Ols-1 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ai-inference-server-3 | Not specified | Not specified |
| ADP | Red Hat | Ols-1 | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Rhel-ai-3 | Not specified | Not specified |
| ADP | Red Hat | Openshift-hosted-osd4 | Not specified | Not specified |
| ADP | Red Hat | Rhel-ai-3 | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Rhel-ai-3 | Not specified | Not specified |
| ADP | Red Hat | Rhel-ai-3 | Not specified | Not specified |
| ADP | Red Hat | Rhel-ai-3 | Not specified | Not specified |
| ADP | Red Hat | Rhel-ai-3 | Not specified | Not specified |
| ADP | Red Hat | Rhel-ai-3 | Not specified | Not specified |
| ADP | Red Hat | Rhn Satellite 6 | Not specified | Not specified |
| ADP | Red Hat | Rhel-cla-0 | Not specified | Not specified |
| ADP | Red Hat | Rhel-ai-3 | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Services-ansible-lightspeed-chatbot | Not specified | Not specified |
| ADP | Red Hat | Rhn Satellite 6 | Not specified | Not specified |
| ADP | Red Hat | Rhn Satellite 6 | Not specified | Not specified |
| ADP | Red Hat | Rhn Satellite 6 | Not specified | Not specified |
| ADP | Red Hat | Rhn Satellite 6 | Not specified | Not specified |
| ADP | Red Hat | Rhn Satellite 6 | Not specified | Not specified |
| ADP | Red Hat | Openshift-ai | Not specified | Not specified |
| ADP | Red Hat | Rhn Satellite 6 | Not specified | Not specified |
| ADP | Red Hat | Services-ansible-lightspeed-chatbot | Not specified | Not specified |
| ADP | Red Hat | Services-ansible-lightspeed-chatbot | Not specified | Not specified |
| ADP | Red Hat | Rhn Satellite 6 | Not specified | Not specified |
| ADP | Red Hat | Rhn Satellite 6 | Not specified | Not specified |
| ADP | Red Hat | Services-ansible-nexus | Not specified | Not specified |
| ADP | Red Hat | Services-inventory | Not specified | Not specified |
| ADP | Red Hat | Services-inventory | Not specified | Not specified |
| ADP | Red Hat | Services-ansible-lightspeed-chatbot | Not specified | Not specified |
| ADP | Red Hat | Services-management-platform | Not specified | Not specified |
| ADP | Red Hat | Services-digital-roadmap | Not specified | Not specified |
| ADP | Red Hat | Services-ansible-on-clouds | Not specified | Not specified |
| ADP | Red Hat | Services-management-platform | Not specified | Not specified |
| ADP | Red Hat | Services-ansible-lightspeed-chatbot | Not specified | Not specified |
| ADP | Red Hat | Services-rhel-lightspeed | Not specified | Not specified |
| ADP | Red Hat | Services-lightspeed-agent-google-cloud | Not specified | Not specified |
| ADP | Red Hat | Services-vulnerability-engine | Not specified | Not specified |
| ADP | Red Hat | Services-vulnerability-engine | Not specified | Not specified |
| ADP | Red Hat | Services-vulnerability-engine | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.secwest.net/starlette | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | www.secwest.net | Exploit, Mitigation, Third Party Advisory |
| security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48710.json | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | security.access.redhat.com | |
| ostif.org/disclosing-the-badhost-vulnerability-in-starlette | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | ostif.org | Mitigation, Third Party Advisory |
| www.cve.org/CVERecord | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | www.cve.org | |
| www.x41-dsec.de/lab/advisories/x41-2026-002-starlette | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | www.x41-dsec.de | Exploit, Mitigation, Third Party Advisory |
| access.redhat.com/security/cve/CVE-2026-48710 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| github.com/pypa/advisory-database/tree/main/vulns/starlette/PYSEC-2026-1... | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | github.com | Third Party Advisory |
| badhost.org | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | badhost.org | Mitigation, Third Party Advisory |
| github.com/Kludex/starlette/security/advisories/GHSA-86qp-5c8j-p5mr | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | github.com | Vendor Advisory |
| github.com/Kludex/starlette/commit/764dab0dcfb9033d75442d7a359645c9f94648c6 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | github.com | Patch |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-05-26T23:01:03.204Z | Reported to Red Hat. |
| ADP | 2026-05-26T21:54:54.393Z | Made public. |
There are currently no legacy QID mappings associated with this CVE.