From 9a33b37a0dcebcb0ae41a898e16a87667ee41c29 Mon Sep 17 00:00:00 2001
From: Dream <2468001320@qq.com>
Date: Fri, 28 Aug 2026 10:56:49 +0800
Subject: [PATCH] fix: sort RFC 2231 parameter continuations numerically

Fixes #13499
---
 aiohttp/multipart.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/aiohttp/multipart.py b/aiohttp/multipart.py
index e965756dad1..5a35c0f2777 100644
--- a/aiohttp/multipart.py
+++ b/aiohttp/multipart.py
@@ -204,7 +204,8 @@ def content_disposition_filename(
     else:
         parts = []
         fnparams = sorted(
-            (key, value) for key, value in params.items() if key.startswith(name_suf)
+            ((key, value) for key, value in params.items() if key.startswith(name_suf)),
+            key=lambda kv: int(kv[0].split("*", 1)[1].rstrip("*")),
         )
         for num, (key, value) in enumerate(fnparams):
             _, tail = key.split("*", 1)