diff --git a/pkgs/by-name/pa/pantalaimon/package.nix b/pkgs/by-name/pa/pantalaimon/package.nix
index a362b7ede8ab..8f34959791d7 100644
--- a/pkgs/by-name/pa/pantalaimon/package.nix
+++ b/pkgs/by-name/pa/pantalaimon/package.nix
@@ -93,5 +93,10 @@ python3Packages.buildPythonApplication rec {
     homepage = "https://github.com/matrix-org/pantalaimon";
     license = lib.licenses.asl20;
     maintainers = with lib.maintainers; [ valodim ];
+    knownVulnerabilities = [
+      ''
+        pantalaimon was archived upstream, the last activity was from 4. June 2025.
+      ''
+    ];
   };
 }