CVE-2026-54387
Tinyproxy - HTTP Request Smuggling via CL/TE Desynchronization
CVSS Score
9.1
EPSS Score
0.0%
EPSS Percentile
0th
Tinyproxy through 1.11.3, fixed in commit ff45d3b, fails to reconcile conflicting Content-Length and Transfer-Encoding: chunked headers, forwarding both verbatim to the backend while using Content-Length to determine how many request body bytes to consume. Remote attackers can desynchronize the proxy and backend parser state, allowing injection of arbitrary HTTP requests to the backend to enable cache poisoning, access control bypass, and request hijacking.
| CWE | CWE-444 |
| Vendor | tinyproxy |
| Product | tinyproxy |
| Published | Jun 17, 2026 |
| Last Updated | Jun 17, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Affected Versions
tinyproxy / tinyproxy
0 ≤ 1.11.3
References
github.com: https://github.com/tinyproxy/tinyproxy/issues/609 github.com: https://github.com/tinyproxy/tinyproxy/pull/610 github.com: https://github.com/tinyproxy/tinyproxy/commit/ff45d3bf0e61d0f8ed97ab379d3047f04eb67521 vulncheck.com: https://www.vulncheck.com/advisories/tinyproxy-http-request-smuggling-via-cl-te-desynchronization
Credits
Tristan Madani (@TristanInSec)