diff --git a/pkgs/by-name/sh/shader-slang/1-find-packages.patch b/pkgs/by-name/sh/shader-slang/1-find-packages.patch
deleted file mode 100644
index 5f98b301c8b58..0000000000000
--- a/pkgs/by-name/sh/shader-slang/1-find-packages.patch
+++ /dev/null
@@ -1,83 +0,0 @@
-diff --git a/CMakeLists.txt b/CMakeLists.txt
-index 549e465ac..546c94607 100644
---- a/CMakeLists.txt
-+++ b/CMakeLists.txt
-@@ -175,6 +175,8 @@ advanced_option(
-     "Build using system unordered dense"
-     OFF
- )
-+advanced_option(SLANG_USE_SYSTEM_SPIRV_TOOLS "Build using system SPIR-V tools library" OFF)
-+advanced_option(SLANG_USE_SYSTEM_GLSLANG "Build using system glslang library" OFF)
- 
- option(
-     SLANG_SPIRV_HEADERS_INCLUDE_DIR
-@@ -404,6 +406,34 @@ if(${SLANG_USE_SYSTEM_UNORDERED_DENSE})
-     find_package(unordered_dense CONFIG QUIET)
- endif()
- 
-+if(${SLANG_USE_SYSTEM_MINIZ})
-+    find_package(miniz REQUIRED)
-+    add_library(miniz ALIAS miniz::miniz)
-+endif()
-+
-+if(${SLANG_USE_SYSTEM_LZ4})
-+    find_package(lz4 REQUIRED)
-+    add_library(lz4_static ALIAS LZ4::lz4)
-+endif()
-+
-+if(${SLANG_USE_SYSTEM_VULKAN_HEADERS})
-+    find_package(VulkanHeaders REQUIRED)
-+endif()
-+
-+if(${SLANG_USE_SYSTEM_SPIRV_HEADERS})
-+    find_package(SPIRV-Headers REQUIRED)
-+    add_library(SPIRV-Headers ALIAS SPIRV-Headers::SPIRV-Headers)
-+endif()
-+
-+if(${SLANG_USE_SYSTEM_SPIRV_TOOLS})
-+    find_package(SPIRV-Tools REQUIRED)
-+endif()
-+
-+if(${SLANG_USE_SYSTEM_GLSLANG})
-+    find_package(glslang REQUIRED)
-+    add_library(glslang ALIAS glslang::glslang)
-+endif()
-+
- add_subdirectory(external)
- 
- # webgpu_dawn is only available as a fetched shared library, since Dawn's nested source
-diff --git a/external/CMakeLists.txt b/external/CMakeLists.txt
-index 801cae4d6..d45150118 100644
---- a/external/CMakeLists.txt
-+++ b/external/CMakeLists.txt
-@@ -133,6 +133,7 @@ if(SLANG_ENABLE_SLANG_GLSLANG)
-         )
-     endif()
- 
-+if(NOT ${SLANG_USE_SYSTEM_SPIRV_TOOLS})
-     # SPIRV-Tools
-     set(SPIRV_TOOLS_BUILD_STATIC ON)
-     set(SPIRV_WERROR OFF)
-@@ -148,11 +149,14 @@ if(SLANG_ENABLE_SLANG_GLSLANG)
-             ${system}
-         )
-     endif()
-+endif()
- 
-+if(NOT ${SLANG_USE_SYSTEM_GLSLANG})
-     # glslang
-     set(SKIP_GLSLANG_INSTALL ON)
-     set(ENABLE_OPT ON)
-     set(ENABLE_PCH OFF)
-+    set(ALLOW_EXTERNAL_SPIRV_TOOLS ${SLANG_USE_SYSTEM_SPIRV_TOOLS})
-     if(NOT SLANG_OVERRIDE_GLSLANG_PATH)
-         add_subdirectory(glslang EXCLUDE_FROM_ALL ${system})
-     else()
-@@ -164,6 +168,7 @@ if(SLANG_ENABLE_SLANG_GLSLANG)
-         )
-     endif()
- endif()
-+endif()
- 
- # imgui
- add_library(imgui INTERFACE)
diff --git a/pkgs/by-name/sh/shader-slang/2-shared-llvm.patch b/pkgs/by-name/sh/shader-slang/1-shared-llvm.patch
similarity index 100%
rename from pkgs/by-name/sh/shader-slang/2-shared-llvm.patch
rename to pkgs/by-name/sh/shader-slang/1-shared-llvm.patch
diff --git a/pkgs/by-name/sh/shader-slang/3-glslang-15.patch b/pkgs/by-name/sh/shader-slang/2-glslang-15.patch
similarity index 100%
rename from pkgs/by-name/sh/shader-slang/3-glslang-15.patch
rename to pkgs/by-name/sh/shader-slang/2-glslang-15.patch
diff --git a/pkgs/by-name/sh/shader-slang/package.nix b/pkgs/by-name/sh/shader-slang/package.nix
index b45b51197a478..d7199d6879c47 100644
--- a/pkgs/by-name/sh/shader-slang/package.nix
+++ b/pkgs/by-name/sh/shader-slang/package.nix
@@ -10,7 +10,7 @@
   libxml2,
   libX11,
   glslang,
-  llvmPackages_13,
+  llvmPackages_14,
   versionCheckHook,
   gitUpdater,
 
@@ -27,33 +27,26 @@
 
 stdenv.mkDerivation (finalAttrs: {
   pname = "shader-slang";
-  version = "2025.14.3";
+  version = "2025.15";
 
   src = fetchFromGitHub {
     owner = "shader-slang";
     repo = "slang";
     tag = "v${finalAttrs.version}";
-    hash = "sha256-tHLm0XmS5vV+o3VmFHWG8wZnrb0p63Nz1zVyvc/e5+s=";
+    hash = "sha256-m1Xn8OybEDJYrR5c5eJZNvDhXtnydQ5lx1v2PqyJu5c=";
     fetchSubmodules = true;
   };
 
-  patches = [
-    # Slang's build definitions do not support using system provided cmake packages
-    # for its dependencies.
-    # While it does come with "SLANG_USE_SYSTEM_XYZ" flags, these expect Slang to be
-    # imported into some other CMake build that already provides the necessary target.
-    # This patch adds the required `find_package` calls and sets up target aliases where needed.
-    ./1-find-packages.patch
-  ]
-  ++ lib.optionals withSharedLLVM [
-    # Upstream statically links libllvm and libclang++, resulting in a ~5x increase in binary size.
-    ./2-shared-llvm.patch
-  ]
-  ++ lib.optionals withGlslang [
-    # Upstream depends on glslang 13 and there are minor breaking changes in glslang 15, the version
-    # we ship in nixpkgs.
-    ./3-glslang-15.patch
-  ];
+  patches =
+    lib.optionals withSharedLLVM [
+      # Upstream statically links libllvm and libclang++, resulting in a ~5x increase in binary size.
+      ./1-shared-llvm.patch
+    ]
+    ++ lib.optionals withGlslang [
+      # Upstream depends on glslang 13 and there are minor breaking changes in glslang 15, the version
+      # we ship in nixpkgs.
+      ./2-glslang-15.patch
+    ];
 
   outputs = [
     "out"
@@ -78,10 +71,10 @@ stdenv.mkDerivation (finalAttrs: {
     libX11
   ]
   ++ lib.optionals withLLVM [
-    # Slang only supports LLVM 13:
-    # https://github.com/shader-slang/slang/blob/master/docs/building.md#llvm-support
-    llvmPackages_13.llvm
-    llvmPackages_13.libclang
+    # Slang only supports LLVM 14:
+    # https://github.com/shader-slang/slang/blob/v2025.15/docs/building.md#llvm-support
+    llvmPackages_14.llvm
+    llvmPackages_14.libclang
   ]
   ++ lib.optionals withGlslang [
     # SPIRV-tools is included in glslang.