From 9962fbbe2ed20a95dd1e9533fbc684070347f031 Mon Sep 17 00:00:00 2001
From: dwandw <dwandw@gmail.com>
Date: Tue, 21 Apr 2026 02:27:11 +0000
Subject: [PATCH] fix: IPv6 prefixes not recognized as proxy
 https://github.com/jellyfin/jellyfin/issues/15710

---
 CONTRIBUTORS.md                                  |  1 +
 .../Extensions/ApiServiceCollectionExtensions.cs |  2 +-
 tests/Jellyfin.Server.Tests/ParseNetworkTests.cs | 16 ++++++++--------
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md
index eb2221f2b3..c42962786d 100644
--- a/CONTRIBUTORS.md
+++ b/CONTRIBUTORS.md
@@ -228,6 +228,7 @@
  - [MarcoCoreDuo](https://github.com/MarcoCoreDuo)
  - [LiHRaM](https://github.com/LiHRaM)
  - [MSalman5230](https://github.com/MSalman5230)
+ - [dwandw](https://github.com/dwandw)
 
 # Emby Contributors
 
diff --git a/Jellyfin.Server/Extensions/ApiServiceCollectionExtensions.cs b/Jellyfin.Server/Extensions/ApiServiceCollectionExtensions.cs
index c71c193e2e..a498901481 100644
--- a/Jellyfin.Server/Extensions/ApiServiceCollectionExtensions.cs
+++ b/Jellyfin.Server/Extensions/ApiServiceCollectionExtensions.cs
@@ -312,7 +312,7 @@ namespace Jellyfin.Server.Extensions
                 return;
             }
 
-            if (prefixLength == NetworkConstants.MinimumIPv4PrefixSize)
+            if ((addr.AddressFamily == AddressFamily.InterNetwork && prefixLength == NetworkConstants.MinimumIPv4PrefixSize) || (addr.AddressFamily == AddressFamily.InterNetworkV6 && prefixLength == NetworkConstants.MinimumIPv6PrefixSize))
             {
                 options.KnownProxies.Add(addr);
             }
diff --git a/tests/Jellyfin.Server.Tests/ParseNetworkTests.cs b/tests/Jellyfin.Server.Tests/ParseNetworkTests.cs
index 14f4c33b6b..e788f43b86 100644
--- a/tests/Jellyfin.Server.Tests/ParseNetworkTests.cs
+++ b/tests/Jellyfin.Server.Tests/ParseNetworkTests.cs
@@ -23,8 +23,8 @@ namespace Jellyfin.Server.Tests
                 true,
                 true,
                 new string[] { "192.168.t", "127.0.0.1", "::1", "1234.1232.12.1234" },
-                new IPAddress[] { IPAddress.Loopback },
-                new IPNetwork[] { new IPNetwork(IPAddress.IPv6Loopback, 128) });
+                new IPAddress[] { IPAddress.Loopback, IPAddress.IPv6Loopback },
+                Array.Empty<IPNetwork>());
 
             data.Add(
                 true,
@@ -37,8 +37,8 @@ namespace Jellyfin.Server.Tests
                 true,
                 true,
                 new string[] { "::1" },
-                Array.Empty<IPAddress>(),
-                new IPNetwork[] { new IPNetwork(IPAddress.IPv6Loopback, 128) });
+                new IPAddress[] { IPAddress.IPv6Loopback },
+                Array.Empty<IPNetwork>());
 
             data.Add(
                 false,
@@ -58,15 +58,15 @@ namespace Jellyfin.Server.Tests
                 false,
                 true,
                 new string[] { "localhost" },
-                Array.Empty<IPAddress>(),
-                new IPNetwork[] { new IPNetwork(IPAddress.IPv6Loopback, 128) });
+                new IPAddress[] { IPAddress.IPv6Loopback },
+                Array.Empty<IPNetwork>());
 
             data.Add(
                 true,
                 true,
                 new string[] { "localhost" },
-                new IPAddress[] { IPAddress.Loopback },
-                new IPNetwork[] { new IPNetwork(IPAddress.IPv6Loopback, 128) });
+                new IPAddress[] { IPAddress.Loopback, IPAddress.IPv6Loopback },
+                Array.Empty<IPNetwork>());
             return data;
         }