diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 2aabdc199172..f61add3b6d95 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -5524,7 +5524,13 @@ void PeerManagerImpl::ProcessMessage(
 
     if (msg_type == NetMsgType::SPORK) {
         CSporkMessage spork;
-        vRecv >> spork;
+        try {
+            vRecv >> spork;
+        } catch (const std::ios_base::failure& e) {
+            // Attribute deserialization failures to the peer; the outer catch would otherwise silently drop.
+            Misbehaving(*peer, 100, strprintf("malformed spork received. peer=%d error=%s", pfrom.GetId(), e.what()));
+            return;
+        }
 
         uint256 hash = spork.GetHash();
         CInv spork_inv{MSG_SPORK, hash};
diff --git a/src/spork.h b/src/spork.h
index bb1c03bef74b..9d23fa68b240 100644
--- a/src/spork.h
+++ b/src/spork.h
@@ -109,7 +109,8 @@ class CSporkMessage
 
     SERIALIZE_METHODS(CSporkMessage, obj)
     {
-        READWRITE(obj.nSporkID, obj.nValue, obj.nTimeSigned, obj.vchSig);
+        READWRITE(obj.nSporkID, obj.nValue, obj.nTimeSigned,
+                  LIMITED_VECTOR(obj.vchSig, CPubKey::COMPACT_SIGNATURE_SIZE));
     }
 
     /**
diff --git a/test/functional/feature_sporks.py b/test/functional/feature_sporks.py
index 7940c1aa9b86..522d8f7a58d9 100755
--- a/test/functional/feature_sporks.py
+++ b/test/functional/feature_sporks.py
@@ -3,6 +3,9 @@
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+import struct
+
+from test_framework.messages import ser_compact_size
 from test_framework.p2p import MESSAGEMAP, P2PInterface
 from test_framework.test_framework import BitcoinTestFramework
 
@@ -117,6 +120,14 @@ def run_test(self):
 
         assert "" not in self.nodes[0].spork('show').keys()
 
+        # Oversized signature length prefix must trigger disconnect, not silent drop.
+        MAX_SIZE = 0x02000000
+        bad_spork = msg_spork_raw()
+        bad_spork.raw = struct.pack("<iqq", 10001, 0, 0) + ser_compact_size(MAX_SIZE)
+        bad_peer = self.nodes[0].add_p2p_connection(SporkP2PInterface())
+        bad_peer.send_message(bad_spork)
+        bad_peer.wait_for_disconnect()
+
 
 if __name__ == '__main__':
     SporkTest().main()