Description
Rouille 0.3.3 through 3.6.2 contains an HTTP request smuggling vulnerability that allows remote attackers to desynchronize HTTP message boundaries by exploiting improper header forwarding in the proxy implementation. The proxy in src/proxy.rs forwards the client's Transfer-Encoding header to upstream backends unchanged while transmitting a body already de-chunked by tiny_http, enabling CL.TE desynchronization attacks where attackers control where the backend believes the request body ends.
Published: 2026-07-28
Score: 6.3 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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Tracking

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Advisories

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History

Tue, 28 Jul 2026 17:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Tue, 28 Jul 2026 17:00:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L'}

 cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:L'}

Tue, 28 Jul 2026 16:15:00 +0000

Type Values Removed Values Added
Description Rouille 0.3.3 through 3.6.2 contains an HTTP request smuggling vulnerability that allows remote attackers to desynchronize HTTP message boundaries by exploiting improper header forwarding in the proxy implementation. The proxy in src/proxy.rs forwards the client's Transfer-Encoding header to upstream backends unchanged while transmitting a body already de-chunked by tiny_http, enabling CL.TE desynchronization attacks where attackers control where the backend believes the request body ends.
Title Rouille 0.3.3 - 3.6.2 HTTP Request Smuggling via proxy Transfer-Encoding Header
Weaknesses CWE-444
References
Metrics cvssV3_1

{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-07-28T16:35:34.542Z

Reserved: 2026-07-28T16:06:49.773Z

Link: CVE-2026-67181

cve-icon Vulnrichment

Updated: 2026-07-28T16:35:22.347Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-444

    Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')