diff --git a/pkgs/by-name/ca/catalyst-browser/package.nix b/pkgs/by-name/ca/catalyst-browser/package.nix
deleted file mode 100644
index 97c53a44a57c..000000000000
--- a/pkgs/by-name/ca/catalyst-browser/package.nix
+++ /dev/null
@@ -1,85 +0,0 @@
-{
-  stdenv,
-  lib,
-  fetchurl,
-  appimageTools,
-  makeWrapper,
-  electron_33,
-  electronPackage ? electron_33,
-  asar,
-}:
-
-let
-  electron = electronPackage;
-in
-stdenv.mkDerivation rec {
-  pname = "catalyst-browser";
-  version = "3.9.6";
-
-  src = fetchurl {
-    url = "https://github.com/CatalystDevOrg/Catalyst/releases/download/v${version}/catalyst-${version}.AppImage";
-    hash = "sha256-aqEwVykPt6p3HjDAsr7N/+uHnEK5yTUAgCsaT7OmI0w=";
-    name = "catalyst-${version}.AppImage";
-  };
-
-  appimageContents = appimageTools.extractType2 {
-    inherit pname src version;
-  };
-
-  dontUnpack = true;
-  dontConfigure = true;
-  dontBuild = true;
-
-  nativeBuildInputs = [
-    makeWrapper
-    asar
-  ];
-
-  installPhase = ''
-    runHook preInstall
-
-    mkdir -p $out/bin $out/share/catalyst $out/share/applications
-    mkdir -p $out/share/catalyst/resources/
-
-    cp -a ${appimageContents}/locales $out/share/catalyst
-    cp -a ${appimageContents}/catalyst.desktop $out/share/applications/catalyst.desktop
-    mkdir -p $out/share/pixmaps
-    cp -r ${appimageContents}/usr/share/icons/hicolor/1080x1080/apps/catalyst.png $out/share/pixmaps/
-    asar extract ${appimageContents}/resources/app.asar resources/
-    rm -rf resources/.github
-    rm -rf resources/.vscode
-    rm -rf resources/.eslintrc.json
-    rm -rf resources/.gitignore
-    rm -rf resources/.pnpm-debug.log
-    rm -rf resources/contributing.md
-    rm -rf resources/pnpm-lock.yaml
-    rm -rf resources/README.md
-    rm -rf resources/CODE_OF_CONDUCT.md
-    rm -rf *.nix
-    substituteInPlace resources/src/index.html \
-      --replace-fail 'catalyst-default-distrib' 'catalyst-default-nixpkgs'
-
-    substituteInPlace $out/share/applications/catalyst.desktop \
-      --replace-fail 'Exec=AppRun' 'Exec=${meta.mainProgram}'
-
-    asar pack resources/ $out/share/catalyst/resources/app.asar
-
-    runHook postInstall
-  '';
-
-  postFixup = ''
-    makeWrapper ${electron}/bin/electron $out/bin/${meta.mainProgram} \
-      --add-flags $out/share/catalyst/resources/app.asar \
-      --prefix LD_LIBRARY_PATH : "${lib.makeLibraryPath [ stdenv.cc.cc ]}"
-  '';
-
-  meta = {
-    description = "Minimal, functional, and customizable user-focused FOSS web browser based on Chromium";
-    homepage = "https://getcatalyst.eu.org";
-    license = lib.licenses.mit;
-    mainProgram = "catalyst";
-    maintainers = with lib.maintainers; [ jdev082 ];
-    platforms = [ "x86_64-linux" ];
-    sourceProvenance = [ lib.sourceTypes.binaryNativeCode ];
-  };
-}
diff --git a/pkgs/top-level/aliases.nix b/pkgs/top-level/aliases.nix
index cd8ccf6d6068..ea48f562a588 100644
--- a/pkgs/top-level/aliases.nix
+++ b/pkgs/top-level/aliases.nix
@@ -412,6 +412,7 @@ mapAliases {
   cassandra_3_0 = throw "'cassandra_3_0' has been removed has it reached end-of-life"; # Added 2025-03-23
   cassandra_3_11 = throw "'cassandra_3_11' has been removed has it reached end-of-life"; # Added 2025-03-23
   cawbird = throw "cawbird has been abandoned upstream and is broken anyways due to Twitter closing its API";
+  catalyst-browser = throw "'catalyst-browser' has been removed due to a lack of maintenance and not satisfying our security criteria for browsers."; # Added 2025-06-25
   cde = throw "'cde' has been removed as it is unmaintained and broken"; # Added 2025-05-17
   centerim = throw "centerim has been removed due to upstream disappearing"; # Added 2025-04-18
   certmgr-selfsigned = certmgr; # Added 2023-11-30