Patch nowWhy this label: EPSS 70%

CVE-2026-48710Kludex Starlette HTTP Request/Response Smuggling Vulnerability

Product: Kludex Starlette
Added to CISA KEV: September 2, 2026
Deadline for US federal agencies: September 16, 2026
Known ransomware use: Not known
EPSS, next 30 days: 70%, in the top 1% of scored CVEs (Oct 25, 2026)
Weakness: CWE-444

What CISA says

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.

What CISA asks you to do

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 evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Sources

Also exploited recently

Data from CISA's Known Exploited Vulnerabilities catalog (public domain) and FIRST EPSS, refreshed hourly. Rheono did not find or test this vulnerability; this page summarizes public sources.