CVE-2026-48710

Kludex Starlette authentication bypass, confirmed exploited in the wild.

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.

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70%chance of exploitation in the next 30 days (EPSS), 99th percentile

2 Sepadded to CISA's Known Exploited Vulnerabilities list, 2026

16 Sepfederal remediation deadline, already passed

Passedpast the deadline: patch now

CISA's name for it	Kludex Starlette HTTP Request/Response Smuggling Vulnerability
Vendor and product	Kludex · Starlette
Type	authentication bypass · CWE-444
Exploited	Confirmed by CISA listed 2 September 2026
Likelihood	one of the most likely to be exploited of every vulnerability tracked
Deadline	16 September 2026 · already passed
Used in ransomware	Not reported
Advisories	github.com ↗ · www.cisa.gov ↗ · www.cisa.gov ↗ · nvd.nist.gov ↗

What to do

Three steps, in this order

Step 1

Apply the vendor fix and restart the affected service.

Step 2

Put the login or management interface behind a VPN or allow-list; a bypass makes passwords irrelevant.

Step 3

Rotate credentials and session keys the product holds, and review accounts and configuration changes since the listing date.

CISA's required action	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.

CISA's required action

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.

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Questions

CVE-2026-48710 in short

Is CVE-2026-48710 being exploited?

Yes. CISA added CVE-2026-48710 to its Known Exploited Vulnerabilities catalogue on 2 September 2026, which it does only on evidence of exploitation in the wild.

What is the CISA deadline for CVE-2026-48710?

US federal agencies must remediate it by 16 September 2026. Everyone else should treat that date as the latest safe point to patch an internet-facing system.

How likely is CVE-2026-48710 to be exploited in the next 30 days?

FIRST's Exploit Prediction Scoring System gives it 70%, the 99th percentile of every CVE it scores.

How do I fix CVE-2026-48710?

Apply the vendor fix and restart the affected service. Put the login or management interface behind a VPN or allow-list; a bypass makes passwords irrelevant. Rotate credentials and session keys the product holds, and review accounts and configuration changes since the listing date.

Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.