Request smuggling via forwarded framing headers
Published Jul 28, 2026 · Updated Jul 28, 2026
HTTP request smuggling in tomaka Rouille 0.3.3 through 3.6.2 allows remote attackers to desynchronize proxied requests. The proxy functions forward client-supplied Transfer-Encoding and Content-Length headers while copying a body already de-chunked by tiny_http, so backend framing no longer matches the transmitted bytes. Exploitation requires proxy::proxy or proxy::full_proxy and a backend or intermediary that processes the attacker-chosen trailing request.
Summary
What happened
HTTP request smuggling in tomaka Rouille 0.3.3 through 3.6.2 allows remote attackers to desynchronize proxied requests. The proxy functions forward client-supplied Transfer-Encoding and Content-Length headers while copying a body already de-chunked by tiny_http, so backend framing no longer matches the transmitted bytes. Exploitation requires proxy::proxy or proxy::full_proxy and a backend or intermediary that processes the attacker-chosen trailing request.
The record
- CVE
- CVE-2026-67181
- Published
- Jul 28, 2026
- Updated
- Jul 28, 2026
- Vendor
- tomaka
- Product
- Rouille
- Classifications
- CWE-444, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 28, 2026CVE publishedPublication date reported by the CVE source.
- Jul 28, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0.3.3 <=3.6.2
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- HTTP Request Smuggling via Transfer-Encoding Desynchronization proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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