HAProxy through 2.0.32 2.1.x and 2.2.x through 2.2.30 2.3.x and 2.4.x through 2.4.23 2.5.x and 2.6.x before 2.6.15 2.7.x before 2.7.10 and 2.8.x before 2.8.2 forwards empty Content-Length headers violating RFC 9110 section 8.6. In uncommon cases an HTTP/1 server behind HAProxy may interpret the payload as an extra request.

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