Kludex Starlette HTTP Request/Response Smuggling Vulnerability
CVE-2026-48710 Exploited
Kludex Starlette contains a HTTP request/response smuggling vulnerability that could allow attackers to inject paths into the host part, prepending the actual path leading to issues such as authentication bypass when the authentication depends on the reconstructed URL’s path. This vulnerability could be chaned with CVE-2026-42271.
Being exploited in the wild
Catalogued 2 September 2026 · US federal remediation deadline 16 September 2026
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for…
Exploit code is also public: Public PoC · Nuclei template
- NucleiStarlette - Improper Validation of Unsafe Equivalence in Input
- Public PoCeris-ths/supply-chain-guard3 stars
- Public PoCxtremebeing/starlette-host-header-lab1 stars
- Public PoCBhanunamikaze/BadHost-CVE-2026-48710-Exploit1 stars
- Public PoCsb-ox/repro-OXDEV-77637-uv-workspace
- Public PoCCuteeCat/CVE-2026-48710
Assessment
- CVSS
- Not yet scored
- Severity
- Unscored
- Known exploited
- Yes — listed in the CISA KEV catalog
- Exploit availability
- CISA KEV, Public PoC, Nuclei template
- Published
- 2 September 2026
- Last updated
- 2 September 2026
- Affected
- Kludex · Starlette
- Weakness
- CWE-444
At the source
References
Query this programmatically
Agents can read this through the MCP endpoint, or over HTTP:
curl https://www.cve.zerocrew.in/api/cve/CVE-2026-48710