What it is
CVE-2026-48710 is an unauthenticated vulnerability affecting Kludex starlette. Starlette is a lightweight ASGI framework/toolkit. Prior to version 1.0.1, the HTTP `Host` request header was not validated before being...
Vulnerability report
starlette
Kludex / starlette · affected before *
Decision summary
Direct answers before the deeper technical record.
What it is
CVE-2026-48710 is an unauthenticated vulnerability affecting Kludex starlette. Starlette is a lightweight ASGI framework/toolkit. Prior to version 1.0.1, the HTTP `Host` request header was not validated before being...
Is it exploited?
Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.
Who is affected?
Kludex / starlette affected before *.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
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.
Exploitation evidence
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
CISA
Independent exploitation attestation added to the Previdian record.
GitHub
Public scanner or PoC coverage increases practical exploitability.
Per-source evidence links for KEV attestations are available through the Previdian Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2026-09-02 17:31 UTC |
| CVE | 2026-09-02 18:01 UTC |
Detection
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Request targets and User-Agents available in Pro. Callback host details available in Enterprise.
Nuclei template detected 05 Jun 2026.
View Nuclei template (opens in new tab)No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →Scanner and exploit-framework references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-48710.yaml | 05 Jun 2026 |
Risk and context
CVSS v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS
36.3%
Recent mention · Github Advisory Database (PIP)
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...
Read full advisoryThese PoCs are unverified and could contain malware. Use at your own risk.
github · Created 2026-08-11 08:21:36 UTC · 0 stars · AI assessment 85%
CVE-2026-48710漏洞验证代码
nuclei · Created Unknown
Timeline
Exploitation attested by an external source
Listed in the CISA Known Exploited Vulnerabilities catalog
Public proof-of-concept code published
Scanner coverage available
Vulnerability disclosed publicly
Identifier reserved by the CNA
Pro API
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
GET /api/v2/pro/kevs/CVE-2026-48710
Free JSON includes basic KEV fields{
"cve_id": "CVE-2026-48710",
"confidence": "Confirmed",
"cvss_score": 6.5,
"cvss_estimated": false,
"epss_score": 0.36257,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}