CVE-2026-67181

Rouille 0.3.3 - 3.6.2 HTTP Request Smuggling via proxy Transfer-Encoding Header

Published Jul 28, 2026 CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Tomaka
Tomaka rouille
Vendors & Products Tomaka
Tomaka rouille
Type Values Removed Values Added
Metrics ssvc

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

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'}

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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Jul 28, 2026, 4:35 PM
Reserved
Jul 28, 2026, 4:06 PM
Status
Deferred
Published
Jul 28, 2026, 4:20 PM
Modified
Oct 24, 2026, 1:10 PM