bitcoin/doc/release-notes-35182.md

HTTP: RPC / REST

The HTTP server has been rewritten from scratch to replace libevent. (#35182)

libevent has been deprecated as a logging category and will be removed in a future release. At that time configurations like debugexclude=libevent will be invalid.

Certain HTTP edge cases will observe different behavior to be more RFC-compliant:

• Stricter enforcement of maximum headers size (8192 bytes)
• Reject requests with whitespace in header field-names
• "Line Folding" is rejected (whitespace at start of a header line)
• Tolerate % at the end of requested URLs
• Multiple "Content-Length" headers with different values are rejected