diff --git a/pkgs/tools/security/aflplusplus/default.nix b/pkgs/tools/security/aflplusplus/default.nix
index 3f436d650a3f..a9e973f8d00d 100644
--- a/pkgs/tools/security/aflplusplus/default.nix
+++ b/pkgs/tools/security/aflplusplus/default.nix
@@ -37,13 +37,13 @@ let
   libtokencap = callPackage ./libtokencap.nix { inherit aflplusplus; };
   aflplusplus = stdenvNoCC.mkDerivation rec {
     pname = "aflplusplus";
-    version = "4.20c";
+    version = "4.21c";
 
     src = fetchFromGitHub {
       owner = "AFLplusplus";
       repo = "AFLplusplus";
       rev = "refs/tags/v${version}";
-      hash = "sha256-bS4Zxd2CX8m6zxO/izJi7Cj34260mOaU6GWjEj+xEU8=";
+      hash = "sha256-DKwPRxSO+JEJYWLldnfrAYqzwqukNzrbo4R5FzJqzzg=";
     };
 
     enableParallelBuilding = true;
diff --git a/pkgs/tools/security/aflplusplus/qemu.nix b/pkgs/tools/security/aflplusplus/qemu.nix
index 81fed0ad0046..950e4eb85cba 100644
--- a/pkgs/tools/security/aflplusplus/qemu.nix
+++ b/pkgs/tools/security/aflplusplus/qemu.nix
@@ -25,9 +25,9 @@ stdenv.mkDerivation {
   src = fetchFromGitHub {
     owner = "AFLplusplus";
     repo = "qemuafl";
-    # rev origin: https://github.com/AFLplusplus/AFLplusplus/commits/stable/qemu_mode/QEMUAFL_VERSION
-    rev = "40033af00c4c5de172ed4fe60c21b9edbd2c189d";
-    sha256 = "sha256-oK0DLJjXDiQuRlbaNOurvw5vlr9HEeOobNywiFTq7xg=";
+    # rev origin: https://github.com/AFLplusplus/AFLplusplus/blob/v4.21c/qemu_mode/QEMUAFL_VERSION
+    rev = "a6f0632a65e101e680dd72643a6128dd180dff72";
+    sha256 = "sha256-4kaQA5KDUqkK+fbjHg47lxZHRN8JrfSC2zdjrbMbDPo=";
     fetchSubmodules = true;
   };