CVE-2026-54387

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.

CVSS v3 9.1 CRITICAL

9.1^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/tinyproxy/tinyproxy/commit/ff45d3bf0e61d0f8ed97ab379d3047f04eb67521
https://github.com/tinyproxy/tinyproxy/issues/609
https://github.com/tinyproxy/tinyproxy/pull/610
https://www.vulncheck.com/advisories/tinyproxy-http-request-smuggling-via-cl-te-desynchronization

Configurations

No configuration.

History

18 Jun 2026, 14:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-06-17 20:17

Updated : 2026-06-22 18:43

NVD link : CVE-2026-54387

Mitre link : CVE-2026-54387

CVE.ORG link : CVE-2026-54387

JSON object : View

Products Affected

No product.

CWE

CWE-444

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

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