diff --git a/src/libsystemd-network/dhcp-message.c b/src/libsystemd-network/dhcp-message.c
index bf85dd4233..14671a0750 100644
--- a/src/libsystemd-network/dhcp-message.c
+++ b/src/libsystemd-network/dhcp-message.c
@@ -1342,6 +1342,11 @@ static int dhcp_message_verify_header(
         if (iov->iov_len < sizeof(DHCPMessageHeader))
                 return -EBADMSG;
 
+        /* DHCP travels over UDP, so anything larger than the maximum UDP payload cannot be a valid
+         * message and would also be impossible to rebuild as a UDP packet. */
+        if (iov->iov_len > UDP_PAYLOAD_MAX_SIZE)
+                return -EBADMSG;
+
         const DHCPMessageHeader *header = iov->iov_base;
 
         if (!IN_SET(header->op, BOOTREQUEST, BOOTREPLY))
diff --git a/test/fuzz/fuzz-dhcp-client/oversized-message b/test/fuzz/fuzz-dhcp-client/oversized-message
new file mode 100644
index 0000000000..a1b3f69aa8
Binary files /dev/null and b/test/fuzz/fuzz-dhcp-client/oversized-message differ