diff --git a/Jellyfin.Api/Controllers/AudioController.cs b/Jellyfin.Api/Controllers/AudioController.cs
index eed2a51159..eff13a5f0c 100644
--- a/Jellyfin.Api/Controllers/AudioController.cs
+++ b/Jellyfin.Api/Controllers/AudioController.cs
@@ -114,7 +114,7 @@ public class AudioController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -281,7 +281,7 @@ public class AudioController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
diff --git a/Jellyfin.Api/Controllers/DynamicHlsController.cs b/Jellyfin.Api/Controllers/DynamicHlsController.cs
index 9bfb35df89..c126580bf6 100644
--- a/Jellyfin.Api/Controllers/DynamicHlsController.cs
+++ b/Jellyfin.Api/Controllers/DynamicHlsController.cs
@@ -188,7 +188,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -431,7 +431,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -608,7 +608,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -777,7 +777,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -950,7 +950,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -1130,7 +1130,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -1316,7 +1316,7 @@ public class DynamicHlsController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
diff --git a/Jellyfin.Api/Controllers/VideosController.cs b/Jellyfin.Api/Controllers/VideosController.cs
index 7832a88322..a5291364fb 100644
--- a/Jellyfin.Api/Controllers/VideosController.cs
+++ b/Jellyfin.Api/Controllers/VideosController.cs
@@ -337,7 +337,7 @@ public class VideosController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
@@ -578,7 +578,7 @@ public class VideosController : BaseJellyfinApiController
         [FromQuery] int? audioChannels,
         [FromQuery] int? maxAudioChannels,
         [FromQuery] string? profile,
-        [FromQuery] string? level,
+        [FromQuery] [RegularExpression(EncodingHelper.LevelValidationRegex)] string? level,
         [FromQuery] float? framerate,
         [FromQuery] float? maxFramerate,
         [FromQuery] bool? copyTimestamps,
diff --git a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
index 501fbcddad..bcf2880c37 100644
--- a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
+++ b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
@@ -37,6 +37,12 @@ namespace MediaBrowser.Controller.MediaEncoding
         /// </summary>
         public const string ContainerValidationRegex = @"^[a-zA-Z0-9\-\._,|]{0,40}$";
 
+        /// <summary>
+        /// The level validation regex.
+        /// This regular expression matches strings representing a double.
+        /// </summary>
+        public const string LevelValidationRegex = @"-?\d+(?:\.\d+)?";
+
         private const string _defaultMjpegEncoder = "mjpeg";
 
         private const string QsvAlias = "qs";